Merge branch 'master' of https://github.com/z3prover/z3

src/ast/arith_decl_plugin.cpp

@@ -89,7 +89,14 @@ app * arith_decl_plugin::mk_numeral(algebraic_numbers::anum const & val, bool is
         parameter p(idx, true);
         SASSERT(p.is_external());
         func_decl * decl = m_manager->mk_const_decl(m_rootv_sym, m_real_decl, func_decl_info(m_family_id, OP_IRRATIONAL_ALGEBRAIC_NUM, 1, &p));
-        return m_manager->mk_const(decl);
+        app * r = m_manager->mk_const(decl);
+
+        if (log_constant_meaning_prelude(r)) {
+            am().display_root_smt2(m_manager->trace_stream(), val);
+            m_manager->trace_stream() << "\n";
+        }
+
+        return r;
     }
 }
 
@@ -415,6 +422,10 @@ app * arith_decl_plugin::mk_numeral(rational const & val, bool is_int) {
                     r = m_manager->mk_const(m_manager->mk_const_decl(m_intv_sym, m_int_decl, func_decl_info(m_family_id, OP_NUM, 2, p)));
                     m_manager->inc_ref(r);
                     m_small_ints.setx(u_val, r, 0);
+
+                    if (log_constant_meaning_prelude(r)) {
+                        m_manager->trace_stream() << u_val << "\n";
+                    }
                 }
                 return r;
             }
@@ -425,6 +436,10 @@ app * arith_decl_plugin::mk_numeral(rational const & val, bool is_int) {
                     r = m_manager->mk_const(m_manager->mk_const_decl(m_realv_sym, m_real_decl, func_decl_info(m_family_id, OP_NUM, 2, p)));
                     m_manager->inc_ref(r);
                     m_small_reals.setx(u_val, r, 0);
+
+                    if (log_constant_meaning_prelude(r)) {
+                        m_manager->trace_stream() << u_val << "\n";
+                    }
                 }
                 return r;
             }
@@ -436,7 +451,14 @@ app * arith_decl_plugin::mk_numeral(rational const & val, bool is_int) {
         decl = m_manager->mk_const_decl(m_intv_sym, m_int_decl, func_decl_info(m_family_id, OP_NUM, 2, p));
     else
         decl = m_manager->mk_const_decl(m_realv_sym, m_real_decl, func_decl_info(m_family_id, OP_NUM, 2, p));
-    return m_manager->mk_const(decl);
+    app * r = m_manager->mk_const(decl);
+
+    if (log_constant_meaning_prelude(r)) {
+        val.display_smt2(m_manager->trace_stream());
+        m_manager->trace_stream() << "\n";
+    }
+
+    return r;
 }
 
 func_decl * arith_decl_plugin::mk_num_decl(unsigned num_parameters, parameter const * parameters, unsigned arity) {

src/ast/ast.cpp

@@ -28,6 +28,7 @@ Revision History:
 #include "ast/ast_smt2_pp.h"
 #include "ast/array_decl_plugin.h"
 #include "ast/ast_translation.h"
+#include "util/z3_version.h"
 
 
 // -----------------------------------
@@ -662,6 +663,23 @@ ast* ast_table::pop_erase() {
 //
 // -----------------------------------
 
+/**
+     \brief Checks wether a log is being generated and, if necessary, adds the beginning of an "[attach-meaning]" line
+    to that log. The theory solver should add some description of the meaning of the term in terms of the theory's
+    internal reasoning to the end of the line and insert a line break.
+    
+    \param a the term that should be described.
+
+    \return true if a log is being generated, false otherwise.
+*/
+bool decl_plugin::log_constant_meaning_prelude(app * a) {
+    if (m_manager->has_trace_stream()) {
+        m_manager->trace_stream() << "[attach-meaning] #" << a->get_id() << " " << m_manager->get_family_name(m_family_id).str() << " ";
+        return true;
+    }
+    return false;
+}
+
 func_decl * decl_plugin::mk_func_decl(decl_kind k, unsigned num_parameters, parameter const * parameters,
                                         unsigned num_args, expr * const * args, sort * range) {
     ptr_buffer<sort> sorts;
@@ -1347,6 +1365,7 @@ ast_manager::ast_manager(proof_gen_mode m, char const * trace_file, bool is_form
     if (trace_file) {
         m_trace_stream       = alloc(std::fstream, trace_file, std::ios_base::out);
         m_trace_stream_owner = true;
+        *m_trace_stream << "[tool-version] Z3 " << Z3_MAJOR_VERSION << "." << Z3_MINOR_VERSION << "." << Z3_BUILD_NUMBER << "\n";
     }
 
     if (!is_format_manager)
@@ -2183,7 +2202,14 @@ app * ast_manager::mk_app_core(func_decl * decl, unsigned num_args, expr * const
         }
 
         if (m_trace_stream && r == new_node) {
-            *m_trace_stream << "[mk-app] #" << r->get_id() << " ";
+            if (is_proof(r)) {
+                if (decl == mk_func_decl(m_basic_family_id, PR_UNDEF, 0, nullptr, 0, static_cast<expr * const *>(nullptr)))
+                    return r;
+                *m_trace_stream << "[mk-proof] #";
+            } else {
+                *m_trace_stream << "[mk-app] #";
+            }
+            *m_trace_stream << r->get_id() << " ";
             if (r->get_num_args() == 0 && r->get_decl()->get_name() == "int") {
                 ast_ll_pp(*m_trace_stream, *this, r);
             }
@@ -2329,7 +2355,7 @@ var * ast_manager::mk_var(unsigned idx, sort * s) {
     var * r         = register_node(new_node);
 
     if (m_trace_stream && r == new_node) {
-        *m_trace_stream << "[mk-var] #" << r->get_id() << "\n";
+        *m_trace_stream << "[mk-var] #" << r->get_id() << " " << idx << "\n";
     }
     return r;
 }
@@ -2458,6 +2484,11 @@ quantifier * ast_manager::mk_quantifier(quantifier_kind k, unsigned num_decls, s
 
     if (m_trace_stream && r == new_node) {
         trace_quant(*m_trace_stream, r);
+        *m_trace_stream << "[attach-var-names] #" << r->get_id();
+        for (unsigned i = 0; i < num_decls; ++i) {
+            *m_trace_stream << " (|" << decl_names[num_decls - i - 1].str() << "| ; |" << decl_sorts[num_decls - i -1]->get_name().str() << "|)";
+        }
+        *m_trace_stream << "\n";
     }
 
     return r;

src/ast/ast.h

@@ -998,6 +998,17 @@ protected:
 
     virtual void inherit(decl_plugin* other_p, ast_translation& ) { }
 
+    /**
+       \brief Checks wether a log is being generated and, if necessary, adds the beginning of an "[attach-meaning]" line
+       to that log. The theory solver should add some description of the meaning of the term in terms of the theory's
+       internal reasoning to the end of the line and insert a line break.
+       
+       \param a the term that should be described.
+
+       \return true if a log is being generated, false otherwise.
+    */
+    bool log_constant_meaning_prelude(app * a);
+
     friend class ast_manager;
 
 public:

src/ast/bv_decl_plugin.cpp

@@ -868,7 +868,21 @@ app * bv_util::mk_numeral(rational const & val, sort* s) const {
 
 app * bv_util::mk_numeral(rational const & val, unsigned bv_size) const {
     parameter p[2] = { parameter(val), parameter(static_cast<int>(bv_size)) };
-    return m_manager.mk_app(get_fid(), OP_BV_NUM, 2, p, 0, nullptr);
+    app * r = m_manager.mk_app(get_fid(), OP_BV_NUM, 2, p, 0, nullptr);
+
+    if (m_plugin->log_constant_meaning_prelude(r)) {
+        if (bv_size % 4 == 0) {
+            m_manager.trace_stream() << "#x";
+            val.display_hex(m_manager.trace_stream(), bv_size);
+            m_manager.trace_stream() << "\n";
+        } else {
+            m_manager.trace_stream() << "#b";
+            val.display_bin(m_manager.trace_stream(), bv_size);
+            m_manager.trace_stream() << "\n";
+        }
+    }
+
+    return r;
 }
 
 sort * bv_util::mk_sort(unsigned bv_size) {

src/ast/bv_decl_plugin.h

@@ -126,6 +126,7 @@ inline func_decl * get_div0_decl(ast_manager & m, func_decl * decl) {
 }
 
 class bv_decl_plugin : public decl_plugin {
+    friend class bv_util;
 protected:
     symbol m_bv_sym;
     symbol m_concat_sym;
@@ -432,7 +433,53 @@ public:
     app * mk_bvsmul_no_udfl(expr* m, expr* n) { return m_manager.mk_app(get_fid(), OP_BSMUL_NO_UDFL, n, m); }
     app * mk_bvumul_no_ovfl(expr* m, expr* n) { return m_manager.mk_app(get_fid(), OP_BUMUL_NO_OVFL, n, m); }
 
-    app * mk_bv(unsigned n, expr* const* es) { return m_manager.mk_app(get_fid(), OP_MKBV, n, es); }
+    private:
+    void log_bv_from_exprs(app * r, unsigned n, expr* const* es) {
+        if (m_manager.has_trace_stream()) {
+            for (unsigned i = 0; i < n; ++i) {
+                if (!m_manager.is_true(es[i]) && !m_manager.is_false(es[i]))
+                    return;
+            } 
+
+            if (m_plugin->log_constant_meaning_prelude(r)) {
+                if (n % 4 == 0) {
+                    m_manager.trace_stream() << " #x";
+
+                    m_manager.trace_stream() << std::hex;
+                    uint8_t hexDigit = 0;
+                    unsigned curLength = (4 - n % 4) % 4;
+                    for (unsigned i = 0; i < n; ++i) {
+                        hexDigit <<= 1;
+                        ++curLength;
+                        if (m_manager.is_true(es[i])) {
+                            hexDigit |= 1;
+                        }
+                        if (curLength == 4) {
+                            m_manager.trace_stream() << hexDigit;
+                            hexDigit = 0;
+                        }
+                    }
+                    m_manager.trace_stream() << std::dec;
+                } else {
+                    m_manager.trace_stream() << " #b";
+                    for (unsigned i = 0; i < n; ++i) {
+                        m_manager.trace_stream() << (m_manager.is_true(es[i]) ? 1 : 0);
+                    }
+                }
+
+                m_manager.trace_stream() << ")\n";
+            }
+        }
+    }
+
+public:
+    app * mk_bv(unsigned n, expr* const* es) {
+        app * r = m_manager.mk_app(get_fid(), OP_MKBV, n, es);
+
+        log_bv_from_exprs(r, n, es);
+
+        return r;
+    }
 
 };
 

src/ast/datatype_decl_plugin.cpp

@@ -453,6 +453,48 @@ namespace datatype {
             }
         }
 
+        void plugin::log_axiom_definitions(symbol const& s, sort * new_sort) {
+            symbol const& family_name = m_manager->get_family_name(get_family_id());
+            for (constructor const* c : *m_defs[s]) {
+                func_decl_ref f = c->instantiate(new_sort);
+                const unsigned num_args = f->get_arity();
+                if (num_args == 0) continue;
+                for (unsigned i = 0; i < num_args; ++i) {
+                    m_manager->trace_stream() << "[mk-var] " << family_name << "#" << m_id_counter << " " << i << "\n";
+                    ++m_id_counter;
+                }
+                const unsigned constructor_id = m_id_counter;
+                m_manager->trace_stream() << "[mk-app] " << family_name << "#" << constructor_id << " " << f->get_name();
+                for (unsigned i = 0; i < num_args; ++i) {
+                    m_manager->trace_stream() << " " << family_name << "#" << constructor_id - num_args + i;
+                }
+                m_manager->trace_stream() << "\n";
+                ++m_id_counter;
+                m_manager->trace_stream() << "[mk-app] " << family_name << "#" << m_id_counter << " pattern " << family_name << "#" << constructor_id << "\n";
+                ++m_id_counter;
+                m_axiom_bases.insert(f->get_name(), constructor_id + 4);
+                std::ostringstream var_sorts;
+                for (accessor const* a : *c) {
+                    var_sorts << " (;" << a->range()->get_name() << ")";
+                }
+                std::string var_description = var_sorts.str();
+                unsigned i = 0;
+                for (accessor const* a : *c) {
+                    func_decl_ref acc = a->instantiate(new_sort);
+                    m_manager->trace_stream() << "[mk-app] " << family_name << "#" << m_id_counter << " " << acc->get_name() << " " << family_name << "#" << constructor_id << "\n";
+                    ++m_id_counter;
+                    m_manager->trace_stream() << "[mk-app] " << family_name << "#" << m_id_counter << " = " << family_name << "#" << constructor_id - num_args + i 
+                        << " " << family_name << "#" << m_id_counter - 1 << "\n";
+                    ++m_id_counter;
+                    m_manager->trace_stream() << "[mk-quant] " << family_name << "#" << m_id_counter << " constructor_accessor_axiom " << family_name << "#" << constructor_id + 1
+                        << " " << family_name << "#" << m_id_counter - 1 << "\n";
+                    m_manager->trace_stream() << "[attach-var-names] " << family_name << "#" << m_id_counter << var_description << "\n";
+                    ++m_id_counter;
+                    ++i;
+                }
+            }
+        }
+
         bool plugin::mk_datatypes(unsigned num_datatypes, def * const * datatypes, unsigned num_params, sort* const* sort_params, sort_ref_vector & new_sorts) {
             begin_def_block();
             for (unsigned i = 0; i < num_datatypes; ++i) {
@@ -470,6 +512,9 @@ namespace datatype {
             sort_ref_vector ps(*m_manager);
             for (symbol const& s : m_def_block) {                
                 new_sorts.push_back(m_defs[s]->instantiate(ps));
+                if (m_manager->has_trace_stream()) {
+                    log_axiom_definitions(s, new_sorts.back());
+                }
             }
             return true;
         }

src/ast/datatype_decl_plugin.h

@@ -206,13 +206,17 @@ namespace datatype {
         class plugin : public decl_plugin {
             mutable scoped_ptr<util> m_util;
             map<symbol, def*, symbol_hash_proc, symbol_eq_proc> m_defs; 
+            map<symbol, unsigned, symbol_hash_proc, symbol_eq_proc> m_axiom_bases;
+            unsigned                 m_id_counter;
             svector<symbol>          m_def_block;
             unsigned                 m_class_id;
 
             void inherit(decl_plugin* other_p, ast_translation& tr) override;
 
+            void log_axiom_definitions(symbol const& s, sort * new_sort);
+
         public:
-            plugin(): m_class_id(0) {}
+            plugin(): m_id_counter(0), m_class_id(0) {}
             ~plugin() override;
 
             void finalize() override;
@@ -247,6 +251,7 @@ namespace datatype {
             def const& get_def(sort* s) const { return *(m_defs[datatype_name(s)]); }
             def& get_def(symbol const& s) { return *(m_defs[s]); }
             bool is_declared(sort* s) const { return m_defs.contains(datatype_name(s)); }
+            unsigned get_axiom_base_id(symbol const& s) { return m_axiom_bases[s]; }
             util & u() const;
 
         private:

src/ast/fpa_decl_plugin.cpp

@@ -92,7 +92,14 @@ func_decl * fpa_decl_plugin::mk_numeral_decl(mpf const & v) {
 }
 
 app * fpa_decl_plugin::mk_numeral(mpf const & v) {
-    return m_manager->mk_const(mk_numeral_decl(v));
+    app * r = m_manager->mk_const(mk_numeral_decl(v));
+
+    if (log_constant_meaning_prelude(r)) {
+        m_fm.display_smt2(m_manager->trace_stream(), v, false);
+        m_manager->trace_stream() << "\n";
+    }
+
+    return r;
 }
 
 bool fpa_decl_plugin::is_numeral(expr * n, mpf & val) {

src/ast/rewriter/th_rewriter.cpp

@@ -562,6 +562,29 @@ struct th_rewriter_cfg : public default_rewriter_cfg {
     br_status reduce_app(func_decl * f, unsigned num, expr * const * args, expr_ref & result, proof_ref & result_pr) {
         result_pr = nullptr;
         br_status st = reduce_app_core(f, num, args, result);
+
+        if (st != BR_FAILED && m().has_trace_stream()) {
+            family_id fid = f->get_family_id();
+            if (fid == m_b_rw.get_fid()) {
+                decl_kind k = f->get_decl_kind();
+                if (k == OP_EQ) {
+                    SASSERT(num == 2);
+                    fid = m().get_sort(args[0])->get_family_id();
+                }
+                else if (k == OP_ITE) {
+                    SASSERT(num == 3);
+                    fid = m().get_sort(args[1])->get_family_id();
+                }
+            }
+            app_ref tmp(m());
+            tmp = m().mk_app(f, num, args);
+            m().trace_stream() << "[inst-discovered] theory-solving " << static_cast<void *>(nullptr) << " " << m().get_family_name(fid) << "# ; #" << tmp->get_id() << "\n";
+            tmp = m().mk_eq(tmp, result);
+            m().trace_stream() << "[instance] " << static_cast<void *>(nullptr) << " #" << tmp->get_id() << "\n";
+            m().trace_stream() << "[attach-enode] #" << tmp->get_id() << " 0\n";
+            m().trace_stream() << "[end-of-instance]\n";
+        }
+
         if (st != BR_DONE && st != BR_FAILED) {
             CTRACE("th_rewriter_step", st != BR_FAILED,
                    tout << f->get_name() << "\n";

src/smt/smt_context.cpp

@@ -59,6 +59,7 @@ namespace smt {
         m_b_internalized_stack(m),
         m_e_internalized_stack(m),
         m_final_check_idx(0),
+        m_is_auxiliary(false),
         m_cg_table(m),
         m_dyn_ack_manager(*this, p),
         m_is_diseq_tmp(nullptr),
@@ -238,6 +239,7 @@ namespace smt {
 
     context * context::mk_fresh(symbol const * l, smt_params * p, params_ref const& pa) {
         context * new_ctx = alloc(context, m_manager, p ? *p : m_fparams, pa);
+        new_ctx->m_is_auxiliary = true;
         new_ctx->set_logic(l == nullptr ? m_setup.get_logic() : *l);
         copy_plugins(*this, *new_ctx);
         return new_ctx;
@@ -1941,7 +1943,7 @@ namespace smt {
     */
     void context::push_scope() {
 
-        if (m_manager.has_trace_stream())
+        if (m_manager.has_trace_stream() && !m_is_auxiliary)
             m_manager.trace_stream() << "[push] " << m_scope_lvl << "\n";
 
         m_scope_lvl++;
@@ -2392,7 +2394,7 @@ namespace smt {
     unsigned context::pop_scope_core(unsigned num_scopes) {
 
         try {
-            if (m_manager.has_trace_stream())
+            if (m_manager.has_trace_stream() && !m_is_auxiliary)
                 m_manager.trace_stream() << "[pop] " << num_scopes << " " << m_scope_lvl << "\n";
 
             TRACE("context", tout << "backtracking: " << num_scopes << " from " << m_scope_lvl << "\n";);
@@ -3331,7 +3333,7 @@ namespace smt {
        Return true if succeeded.
     */
     bool context::check_preamble(bool reset_cancel) {
-        if (m_manager.has_trace_stream())
+        if (m_manager.has_trace_stream() && !m_is_auxiliary)
             m_manager.trace_stream() << "[begin-check] " << m_scope_lvl << "\n";
 
         if (memory::above_high_watermark()) {
@@ -3946,7 +3948,7 @@ namespace smt {
                            << mk_pp(bool_var2expr(l.var()), m_manager) << "\n";
                   });
 
-            if (m_manager.has_trace_stream()) {
+            if (m_manager.has_trace_stream() && !m_is_auxiliary) {
                 m_manager.trace_stream() << "[conflict] ";
                 display_literals(m_manager.trace_stream(), num_lits, lits);
                 m_manager.trace_stream() << "\n";

src/smt/smt_context.h

@@ -106,6 +106,8 @@ namespace smt {
 
         unsigned                    m_final_check_idx; // circular counter used for implementing fairness
 
+        bool                        m_is_auxiliary; // used to prevent unwanted information from being logged.
+
         // -----------------------------------
         //
         // Equality & Uninterpreted functions

src/smt/smt_internalizer.cpp

@@ -1019,15 +1019,7 @@ namespace smt {
         sort * s    = term->get_decl()->get_range();
         theory * th = m_theories.get_plugin(s->get_family_id());
         if (th) {
-            if (m_manager.has_trace_stream()) {
-                m_manager.trace_stream() << "[theory-constraints] " << m_manager.get_family_name(s->get_family_id()) << "\n";
-            }
-
             th->apply_sort_cnstr(e, s);
-
-            if (m_manager.has_trace_stream()) {
-                m_manager.trace_stream() << "[end-theory-constraints]\n";
-            }
         }
     }
 

src/smt/smt_quantifier.cpp

@@ -32,6 +32,98 @@ namespace smt {
 
     quantifier_manager_plugin * mk_default_plugin();
 
+    void log_single_justification(std::ostream & out, enode *en, obj_hashtable<enode> &visited, context &ctx, ast_manager &m);
+
+    /**
+         \brief Ensures that all relevant proof steps to explain why the enode is equal to the root of its
+        equivalence class are in the log and up-to-date.
+    */
+    void quantifier_manager::log_justification_to_root(std::ostream & out, enode *en, obj_hashtable<enode> &visited, context &ctx, ast_manager &m) {
+        enode *root = en->get_root();
+        for (enode *it = en; it != root; it = it->get_trans_justification().m_target) {
+            if (visited.find(it) == visited.end()) visited.insert(it);
+            else break;
+
+            if (!it->m_proof_is_logged) {
+                log_single_justification(out, it, visited, ctx, m);
+                it->m_proof_is_logged = true;
+            } else if (it->get_trans_justification().m_justification.get_kind() == smt::eq_justification::kind::CONGRUENCE) {
+
+                // When the justification of an argument changes m_proof_is_logged is not reset => We need to check if the proofs of all arguments are logged.
+                const unsigned num_args = it->get_num_args();
+                enode *target = it->get_trans_justification().m_target;
+
+                for (unsigned i = 0; i < num_args; ++i) {
+                    log_justification_to_root(out, it->get_arg(i), visited, ctx, m);
+                    log_justification_to_root(out, target->get_arg(i), visited, ctx, m);
+                }
+                it->m_proof_is_logged = true;
+            }
+        }
+        if (!root->m_proof_is_logged) {
+            out << "[eq-expl] #" << root->get_owner_id() << " root\n";
+            root->m_proof_is_logged = true;
+        }
+    }
+
+    /**
+         \brief Logs a single equality explanation step and, if necessary, recursively calls log_justification_to_root to log
+        equalities needed by the step (e.g. argument equalities for congruence steps).
+    */
+    void log_single_justification(std::ostream & out, enode *en, obj_hashtable<enode> &visited, context &ctx, ast_manager &m) {
+        smt::literal lit;
+        unsigned num_args;
+        enode *target = en->get_trans_justification().m_target;
+        theory_id th_id;
+
+        switch (en->get_trans_justification().m_justification.get_kind()) {
+        case smt::eq_justification::kind::EQUATION:
+            lit = en->get_trans_justification().m_justification.get_literal();
+            out << "[eq-expl] #" << en->get_owner_id() << " lit #" << ctx.bool_var2expr(lit.var())->get_id() << " ; #" << target->get_owner_id() << "\n";
+            break;
+        case smt::eq_justification::kind::AXIOM:
+            out << "[eq-expl] #" << en->get_owner_id() << " ax ; #" << target->get_owner_id() << "\n";
+            break;
+        case smt::eq_justification::kind::CONGRUENCE:
+            if (!en->get_trans_justification().m_justification.used_commutativity()) {
+                num_args = en->get_num_args();
+
+                for (unsigned i = 0; i < num_args; ++i) {
+                    quantifier_manager::log_justification_to_root(out, en->get_arg(i), visited, ctx, m);
+                    quantifier_manager::log_justification_to_root(out, target->get_arg(i), visited, ctx, m);
+                }
+
+                out << "[eq-expl] #" << en->get_owner_id() << " cg";
+                for (unsigned i = 0; i < num_args; ++i) {
+                    out << " (#" << en->get_arg(i)->get_owner_id() << " #" << target->get_arg(i)->get_owner_id() << ")";
+                }
+                out << " ; #" << target->get_owner_id() << "\n";
+
+                break;
+            } else {
+
+                // The e-graph only supports commutativity for binary functions
+                out << "[eq-expl] #" << en->get_owner_id()
+                    << " cg (#" << en->get_arg(0)->get_owner_id() << " #" << target->get_arg(1)->get_owner_id()
+                    << ") (#" << en->get_arg(1)->get_owner_id() << " #" << target->get_arg(0)->get_owner_id()
+                    << ") ; #" << target->get_owner_id() << "\n";
+                break;
+            }
+        case smt::eq_justification::kind::JUSTIFICATION:
+            th_id = en->get_trans_justification().m_justification.get_justification()->get_from_theory();
+            if (th_id != null_theory_id) {
+                symbol const theory = m.get_family_name(th_id);
+                out << "[eq-expl] #" << en->get_owner_id() << " th " << theory.str() << " ; #" << target->get_owner_id() << "\n";
+            } else {
+                out << "[eq-expl] #" << en->get_owner_id() << " unknown ; #" << target->get_owner_id() << "\n";
+            }
+            break;
+        default:
+            out << "[eq-expl] #" << en->get_owner_id() << " unknown ; #" << target->get_owner_id() << "\n";
+            break;
+        }
+    }
+
     struct quantifier_manager::imp {
         quantifier_manager &                   m_wrapper;
         context &                              m_context;
@@ -105,138 +197,58 @@ namespace smt {
             return m_plugin->is_shared(n);
         }
 
-        /**
-           \brief Ensures that all relevant proof steps to explain why the enode is equal to the root of its
-           equivalence class are in the log and up-to-date.
-        */
-        void log_justification_to_root(std::ostream & out, enode *en, obj_hashtable<enode> &visited) {
-            enode* root = en->get_root();
-            for (enode *it = en; it != root && !visited.contains(it); it = it->get_trans_justification().m_target) {
-
-                visited.insert(it);
-
-                if (!it->m_proof_is_logged) {
-                    log_single_justification(out, it, visited);
-                    it->m_proof_is_logged = true;
-                } 
-                else if (it->get_trans_justification().m_justification.get_kind() == smt::eq_justification::kind::CONGRUENCE) {
-
-                    // When the justification of an argument changes m_proof_is_logged 
-                    // is not reset => We need to check if the proofs of all arguments are logged.
-                    const unsigned num_args = it->get_num_args();
-                    enode *target = it->get_trans_justification().m_target;
-
-                    for (unsigned i = 0; i < num_args; ++i) {
-                        log_justification_to_root(out, it->get_arg(i), visited);
-                        log_justification_to_root(out, target->get_arg(i), visited);
-                    }
-                    SASSERT(it->m_proof_is_logged);
-                }
-            }
-            if (!root->m_proof_is_logged) {
-                out << "[eq-expl] #" << root->get_owner_id() << " root\n";
-                root->m_proof_is_logged = true;
-            }
-        }
-
-        /**
-          \brief Logs a single equality explanation step and, if necessary, recursively calls log_justification_to_root to log
-          equalities needed by the step (e.g. argument equalities for congruence steps).
-        */
-        void log_single_justification(std::ostream & out, enode *en, obj_hashtable<enode> &visited) {
-            smt::literal lit;
-            unsigned num_args;
-            enode *target = en->get_trans_justification().m_target;
-            theory_id th_id;
-
-            switch (en->get_trans_justification().m_justification.get_kind()) {
-            case smt::eq_justification::kind::EQUATION:
-                lit = en->get_trans_justification().m_justification.get_literal();
-                out << "[eq-expl] #" << en->get_owner_id() << " lit #" << m_context.bool_var2expr(lit.var())->get_id() << " ; #" << target->get_owner_id() << "\n";
-                break;
-            case smt::eq_justification::kind::AXIOM:
-                out << "[eq-expl] #" << en->get_owner_id() << " ax ; #" << target->get_owner_id() << "\n";
-                break;
-            case smt::eq_justification::kind::CONGRUENCE:
-                if (!en->get_trans_justification().m_justification.used_commutativity()) {
-                    num_args = en->get_num_args();
-
-                    for (unsigned i = 0; i < num_args; ++i) {
-                        log_justification_to_root(out, en->get_arg(i), visited);
-                        log_justification_to_root(out, target->get_arg(i), visited);
-                    }
-
-                    out << "[eq-expl] #" << en->get_owner_id() << " cg";
-                    for (unsigned i = 0; i < num_args; ++i) {
-                        out << " (#" << en->get_arg(i)->get_owner_id() << " #" << target->get_arg(i)->get_owner_id() << ")";
-                    }
-                    out << " ; #" << target->get_owner_id() << "\n";
-
-                    break;
-                } else {
-                    out << "[eq-expl] #" << en->get_owner_id() << " nyi ; #" << target->get_owner_id() << "\n";
-                    break;
-                }
-            case smt::eq_justification::kind::JUSTIFICATION:
-                th_id = en->get_trans_justification().m_justification.get_justification()->get_from_theory();
-                if (th_id != null_theory_id) {
-                    symbol const theory = m().get_family_name(th_id);
-                    out << "[eq-expl] #" << en->get_owner_id() << " th " << theory.str() << " ; #" << target->get_owner_id() << "\n";
-                } else {
-                    out << "[eq-expl] #" << en->get_owner_id() << " unknown ; #" << target->get_owner_id() << "\n";
-                }
-                break;
-            default:
-                out << "[eq-expl] #" << en->get_owner_id() << " unknown ; #" << target->get_owner_id() << "\n";
-                break;
-            }
-        }
-
         void log_add_instance(
-            fingerprint* f,
-            quantifier * q, app * pat,
-            unsigned num_bindings,
-            enode * const * bindings,
-            vector<std::tuple<enode *, enode *>> & used_enodes) {
+             fingerprint* f,
+             quantifier * q, app * pat,
+             unsigned num_bindings,
+             enode * const * bindings,
+             vector<std::tuple<enode *, enode *>> & used_enodes) {
 
-            std::ostream & out = trace_stream();
-            
-            obj_hashtable<enode> visited;
-            
-            // In the term produced by the quantifier instantiation the root of 
-            // the equivalence class of the terms bound to the quantified variables
-            // is used. We need to make sure that all of these equalities appear in the log.
-            for (unsigned i = 0; i < num_bindings; ++i) {
-                log_justification_to_root(out, bindings[i], visited);
-            }
-            
-            for (auto n : used_enodes) {
-                enode *orig = std::get<0>(n);
-                enode *substituted = std::get<1>(n);
-                if (orig != nullptr) {
-                    log_justification_to_root(out, orig, visited);
-                    log_justification_to_root(out, substituted, visited);
+            if (pat == nullptr) {
+                trace_stream() << "[inst-discovered] MBQI " << static_cast<void*>(f) << " #" << q->get_id();
+                for (unsigned i = 0; i < num_bindings; ++i) {
+                    trace_stream() << " #" << bindings[num_bindings - i - 1]->get_owner_id();
                 }
-            }
-            
-            // At this point all relevant equalities for the match are logged.
-            out << "[new-match] " << static_cast<void*>(f) << " #" << q->get_id() << " #" << pat->get_id();
-            for (unsigned i = 0; i < num_bindings; i++) {
-                // I don't want to use mk_pp because it creates expressions for pretty printing.
-                // This nasty side-effect may change the behavior of Z3.
-                out << " #" << bindings[i]->get_owner_id();
-            }
-            out << " ;";
-            for (auto n : used_enodes) {
-                enode *orig = std::get<0>(n);
-                enode *substituted = std::get<1>(n);
-                if (orig == nullptr)
-                    out << " #" << substituted->get_owner_id();
-                else {
-                    out << " (#" << orig->get_owner_id() << " #" << substituted->get_owner_id() << ")";
+                trace_stream() << "\n";
+            } else {
+                std::ostream & out = trace_stream();
+
+                obj_hashtable<enode> already_visited;
+
+                // In the term produced by the quantifier instantiation the root of the equivalence class of the terms bound to the quantified variables
+                // is used. We need to make sure that all of these equalities appear in the log.
+                for (unsigned i = 0; i < num_bindings; ++i) {
+                    log_justification_to_root(out, bindings[i], already_visited, m_context, m());
                 }
+
+                for (auto n : used_enodes) {
+                    enode *orig = std::get<0>(n);
+                    enode *substituted = std::get<1>(n);
+                    if (orig != nullptr) {
+                        log_justification_to_root(out, orig, already_visited, m_context, m());
+                        log_justification_to_root(out, substituted, already_visited, m_context, m());
+                    }
+                }
+
+                // At this point all relevant equalities for the match are logged.
+                out << "[new-match] " << static_cast<void*>(f) << " #" << q->get_id() << " #" << pat->get_id();
+                for (unsigned i = 0; i < num_bindings; i++) {
+                    // I don't want to use mk_pp because it creates expressions for pretty printing.
+                    // This nasty side-effect may change the behavior of Z3.
+                    out << " #" << bindings[num_bindings - i - 1]->get_owner_id();
+                }
+                out << " ;";
+                for (auto n : used_enodes) {
+                    enode *orig = std::get<0>(n);
+                    enode *substituted = std::get<1>(n);
+                    if (orig == nullptr)
+                        out << " #" << substituted->get_owner_id();
+                    else {
+                        out << " (#" << orig->get_owner_id() << " #" << substituted->get_owner_id() << ")";
+                    }
+                }
+                out << "\n";
             }
-            out << "\n";
         }
 
         bool add_instance(quantifier * q, app * pat,

src/smt/smt_quantifier.h

@@ -52,6 +52,8 @@ namespace smt {
         quantifier_stat * get_stat(quantifier * q) const;
         unsigned get_generation(quantifier * q) const;
 
+        static void log_justification_to_root(std::ostream & log, enode *en, obj_hashtable<enode> &already_visited, context &ctx, ast_manager &m);
+
         bool add_instance(quantifier * q, app * pat,
                           unsigned num_bindings,
                           enode * const * bindings,

src/smt/smt_theory.h

@@ -20,6 +20,7 @@ Revision History:
 #define SMT_THEORY_H_
 
 #include "smt/smt_enode.h"
+#include "smt/smt_quantifier.h"
 #include "util/obj_hashtable.h"
 #include "util/statistics.h"
 #include<typeinfo>
@@ -358,6 +359,67 @@ namespace smt {
         
         std::ostream& display_var_flat_def(std::ostream & out, theory_var v) const { return display_flat_app(out, get_enode(v)->get_owner());  }
 
+    protected:
+        void log_axiom_instantiation(app * r, unsigned axiom_id = UINT_MAX, unsigned num_bindings = 0, app * const * bindings = nullptr, unsigned pattern_id = UINT_MAX, const vector<std::tuple<enode *, enode *>> & used_enodes = vector<std::tuple<enode *, enode*>>()) {
+            ast_manager & m = get_manager();
+            symbol const & family_name = m.get_family_name(get_family_id());
+            if (pattern_id == UINT_MAX) {
+                m.trace_stream() << "[inst-discovered] theory-solving " << static_cast<void *>(nullptr) << " " << family_name << "#";
+                if (axiom_id != UINT_MAX)
+                    m.trace_stream() << axiom_id;
+                for (unsigned i = 0; i < num_bindings; ++i) {
+                    m.trace_stream() << " #" << bindings[i]->get_id();
+                }
+                if (used_enodes.size() > 0) {
+                    m.trace_stream() << " ;";
+                    for (auto n : used_enodes) {
+                        enode *orig = std::get<0>(n);
+                        enode *substituted = std::get<1>(n);
+                        SASSERT(orig == nullptr);
+                        m.trace_stream() << " #" << substituted->get_owner_id();
+                    }
+                }
+            } else {
+                SASSERT(axiom_id != UINT_MAX);
+                obj_hashtable<enode> already_visited;
+                for (auto n : used_enodes) {
+                    enode *orig = std::get<0>(n);
+                    enode *substituted = std::get<1>(n);
+                    if (orig != nullptr) {
+                        quantifier_manager::log_justification_to_root(m.trace_stream(), orig, already_visited, get_context(), get_manager());
+                        quantifier_manager::log_justification_to_root(m.trace_stream(), substituted, already_visited, get_context(), get_manager());
+                    }
+                }
+                m.trace_stream() << "[new-match] " << static_cast<void *>(nullptr) << " " << family_name << "#" << axiom_id << " " << family_name << "#" << pattern_id;
+                for (unsigned i = 0; i < num_bindings; ++i) {
+                    m.trace_stream() << " #" << bindings[i]->get_id();
+                }
+                m.trace_stream() << " ;";
+                for (auto n : used_enodes) {
+                    enode *orig = std::get<0>(n);
+                    enode *substituted = std::get<1>(n);
+                    if (orig == nullptr) {
+                        m.trace_stream() << " #" << substituted->get_owner_id();
+                    } else {
+                        m.trace_stream() << " (#" << orig->get_owner_id() << " #" << substituted->get_owner_id() << ")";
+                    }
+                }
+            }
+            m.trace_stream() << "\n";
+            m.trace_stream() << "[instance] " << static_cast<void *>(nullptr) << " #" << r->get_id() << "\n";
+        }
+
+        void log_axiom_instantiation(expr * r, unsigned axiom_id = UINT_MAX, unsigned num_bindings = 0, app * const * bindings = nullptr, unsigned pattern_id = UINT_MAX, const vector<std::tuple<enode *, enode *>> & used_enodes = vector<std::tuple<enode *, enode*>>()) { log_axiom_instantiation(to_app(r), axiom_id, num_bindings, bindings, pattern_id, used_enodes); }
+
+        void log_axiom_instantiation(app * r, unsigned num_blamed_enodes, enode ** blamed_enodes) {
+            vector<std::tuple<enode *, enode *>> used_enodes;
+            for (unsigned i = 0; i < num_blamed_enodes; ++i) {
+                used_enodes.push_back(std::make_tuple(nullptr, blamed_enodes[i]));
+            }
+            log_axiom_instantiation(r, UINT_MAX, 0, nullptr, UINT_MAX, used_enodes);
+        }
+
+    public:
         /**
            \brief Assume eqs between variable that are equal with respect to the given table.
            Table is a hashtable indexed by the variable value.

src/smt/theory_arith_aux.h

@@ -1239,6 +1239,10 @@ namespace smt {
             farkas.add(abs(pa.get_rational()), to_app(tmp));
         }
         tmp = farkas.get();
+        if (m.has_trace_stream()) {
+            log_axiom_instantiation(tmp);
+            m.trace_stream() << "[end-of-instance]\n";
+        }
         // IF_VERBOSE(1, verbose_stream() << "Farkas result: " << tmp << "\n";);
         atom* a = get_bv2a(m_bound_watch);
         SASSERT(a);

src/smt/theory_arith_core.h

@@ -447,7 +447,14 @@ namespace smt {
               tout << l_ante << "\n" << l_conseq << "\n";);
 
         // literal lits[2] = {l_ante, l_conseq};
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_or(ante, conseq);
+            log_axiom_instantiation(body);
+        }
         mk_clause(l_ante, l_conseq, 0, nullptr);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+
         if (ctx.relevancy()) {
             if (l_ante == false_literal) {
                 ctx.mark_as_relevant(l_conseq);
@@ -528,7 +535,9 @@ namespace smt {
                 expr_ref mod_j(m);
                 while(j < k) {
                     mod_j = m.mk_eq(mod, m_util.mk_numeral(j, true));
+                    if (m.has_trace_stream()) log_axiom_instantiation(mod_j);
                     ctx.internalize(mod_j, false);
+                    if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
                     literal lit(ctx.get_literal(mod_j));
                     lits.push_back(lit);
                     ctx.mark_as_relevant(lit);

src/smt/theory_arith_int.h

@@ -199,6 +199,7 @@ namespace smt {
     void theory_arith<Ext>::branch_infeasible_int_var(theory_var v) {
         SASSERT(is_int(v));
         SASSERT(!get_value(v).is_int());
+        ast_manager & m = get_manager();
         m_stats.m_branches++;
         numeral k     = ceil(get_value(v));
         rational _k   = k.to_rational();
@@ -206,13 +207,19 @@ namespace smt {
               display_var(tout, v);
               tout << "k = " << k << ", _k = "<< _k << std::endl;
               );
-        expr_ref bound(get_manager());
+        expr_ref bound(m);
         expr* e = get_enode(v)->get_owner();
         bound  = m_util.mk_ge(e, m_util.mk_numeral(_k, m_util.is_int(e)));
-        TRACE("arith_int", tout << mk_bounded_pp(bound, get_manager()) << "\n";);
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_or(to_app(bound), m.mk_not(to_app(bound)));
+            log_axiom_instantiation(body);
+        }
+        TRACE("arith_int", tout << mk_bounded_pp(bound, m) << "\n";);
         context & ctx = get_context();
         ctx.internalize(bound, true);
         ctx.mark_as_relevant(bound.get());
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     
@@ -365,6 +372,11 @@ namespace smt {
         mk_polynomial_ge(pol.size(), pol.c_ptr(), unsat_row[0]+rational(1), p2);
         
         context& ctx = get_context();
+        if (get_manager().has_trace_stream()) {
+            app_ref body(get_manager());
+            body = get_manager().mk_or(p1, p2);
+            log_axiom_instantiation(body);
+        }
         ctx.internalize(p1, false);
         ctx.internalize(p2, false);
         literal l1(ctx.get_literal(p1)), l2(ctx.get_literal(p2));
@@ -372,6 +384,7 @@ namespace smt {
         ctx.mark_as_relevant(p2.get());
         
         ctx.mk_th_axiom(get_id(), l1, l2);
+        if (get_manager().has_trace_stream()) get_manager().trace_stream() << "[end-of-instance]\n";
        
         TRACE("arith_int", 
               tout << "cut: (or " << mk_pp(p1, get_manager()) << " " << mk_pp(p2, get_manager()) << ")\n";
@@ -400,7 +413,9 @@ namespace smt {
                 bool _is_int = m_util.is_int(e);
                 expr * bound  = m_util.mk_ge(e, m_util.mk_numeral(rational::zero(), _is_int));
                 context & ctx = get_context();
+                if (get_manager().has_trace_stream()) log_axiom_instantiation(bound);
                 ctx.internalize(bound, true);
+                if (get_manager().has_trace_stream()) get_manager().trace_stream() << "[end-of-instance]\n";
                 ctx.mark_as_relevant(bound);
                 result = true;
             }
@@ -646,7 +661,9 @@ namespace smt {
         TRACE("gomory_cut", tout << "new cut:\n" << bound << "\n"; ante.display(tout););
         literal l     = null_literal;
         context & ctx = get_context();
+        if (get_manager().has_trace_stream()) log_axiom_instantiation(bound);
         ctx.internalize(bound, true);
+        if (get_manager().has_trace_stream()) get_manager().trace_stream() << "[end-of-instance]\n";
         l = ctx.get_literal(bound);
         ctx.mark_as_relevant(l);
         dump_lemmas(l, ante);

src/smt/theory_arith_nl.h

@@ -789,7 +789,14 @@ namespace smt {
             bound  = m_util.mk_eq(var2expr(v), m_util.mk_numeral(rational(0), true));
         TRACE("non_linear", tout << "new bound:\n" << mk_pp(bound, get_manager()) << "\n";);
         context & ctx = get_context();
+        ast_manager & m = get_manager();
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_or(bound, m.mk_not(bound));
+            log_axiom_instantiation(body);
+        }
         ctx.internalize(bound, true);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         ctx.mark_as_relevant(bound);
         literal l     = ctx.get_literal(bound);
         SASSERT(!l.sign());

src/smt/theory_array_base.cpp

@@ -111,7 +111,9 @@ namespace smt {
         if (m.proofs_enabled()) {
             literal l(mk_eq(sel, val, true));
             ctx.mark_as_relevant(l);
+            if (m.has_trace_stream()) log_axiom_instantiation(ctx.bool_var2expr(l.var()));
             assert_axiom(l);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         }
         else {
             TRACE("mk_var_bug", tout << "mk_sel: " << sel->get_id() << "\n";);
@@ -189,7 +191,13 @@ namespace smt {
             TRACE("array_map_bug", tout << "axiom2:\n";
                   tout << mk_ismt2_pp(idx1->get_owner(), m) << "\n=\n" << mk_ismt2_pp(idx2->get_owner(), m);
                   tout << "\nimplies\n" << mk_ismt2_pp(conseq_expr, m) << "\n";);
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_or(ctx.bool_var2expr(ante.var()), conseq_expr);
+                log_axiom_instantiation(body);
+            }
             assert_axiom(ante, conseq);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         }
     }
     
@@ -331,7 +339,13 @@ namespace smt {
         literal sel1_eq_sel2 = mk_eq(sel1, sel2, true);
         ctx.mark_as_relevant(n1_eq_n2);
         ctx.mark_as_relevant(sel1_eq_sel2);
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(m.mk_not(ctx.bool_var2expr(n1_eq_n2.var())), m.mk_not(ctx.bool_var2expr(sel1_eq_sel2.var())));
+            log_axiom_instantiation(body);
+        }
         assert_axiom(n1_eq_n2, ~sel1_eq_sel2);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     bool theory_array_base::can_propagate() {

src/smt/theory_array_full.cpp

@@ -781,8 +781,10 @@ namespace smt {
         else {
             m_eqs.insert(v1, v2, true);
             literal eq(mk_eq(v1, v2, true));
+            if (get_manager().has_trace_stream()) log_axiom_instantiation(get_context().bool_var2expr(eq.var()));
             get_context().mark_as_relevant(eq);            
             assert_axiom(eq);
+            if (get_manager().has_trace_stream()) get_manager().trace_stream() << "[end-of-instance]\n";
 
             // m_eqsv.push_back(eq);
             return true;

src/smt/theory_bv.cpp

@@ -253,9 +253,16 @@ namespace smt {
         enode * e2       = get_enode(v2);
         literal l        = ~(mk_eq(e1->get_owner(), e2->get_owner(), true));
         context & ctx    = get_context();
+        ast_manager & m  = get_manager();
+        expr * eq        = ctx.bool_var2expr(l.var());
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(m.mk_eq(mk_bit2bool(get_enode(v1)->get_owner(), idx), m.mk_not(mk_bit2bool(get_enode(v2)->get_owner(), idx))), m.mk_not(eq));
+            log_axiom_instantiation(body);
+        }
         ctx.mk_th_axiom(get_id(), 1, &l);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         if (ctx.relevancy()) {
-            expr * eq    = ctx.bool_var2expr(l.var());
             relevancy_eh * eh = ctx.mk_relevancy_eh(pair_relevancy_eh(e1->get_owner(), e2->get_owner(), eq));
             ctx.add_relevancy_eh(e1->get_owner(), eh);
             ctx.add_relevancy_eh(e2->get_owner(), eh);
@@ -469,11 +476,17 @@ namespace smt {
             e1 = mk_bit2bool(o1, i);
             e2 = mk_bit2bool(o2, i);
             literal eq = mk_eq(e1, e2, true);
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_not(ctx.bool_var2expr(eq.var())), m.mk_not(ctx.bool_var2expr(oeq.var())));
+                log_axiom_instantiation(body);
+            }
             ctx.mk_th_axiom(get_id(),  l1, ~l2, ~eq);
             ctx.mk_th_axiom(get_id(), ~l1,  l2, ~eq);
             ctx.mk_th_axiom(get_id(),  l1,  l2,  eq);
             ctx.mk_th_axiom(get_id(), ~l1, ~l2,  eq);
             ctx.mk_th_axiom(get_id(), eq, ~oeq);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
             eqs.push_back(~eq);
         }
         eqs.push_back(oeq);
@@ -641,7 +654,9 @@ namespace smt {
               );
        
         ctx.mark_as_relevant(l);
+        if (m.has_trace_stream()) log_axiom_instantiation(ctx.bool_var2expr(l.var()));
         ctx.mk_th_axiom(get_id(), 1, &l);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     void theory_bv::internalize_int2bv(app* n) {    
@@ -684,7 +699,9 @@ namespace smt {
 
         literal l(mk_eq(lhs, rhs, false));
         ctx.mark_as_relevant(l);
+        if (m.has_trace_stream()) log_axiom_instantiation(ctx.bool_var2expr(l.var()));
         ctx.mk_th_axiom(get_id(), 1, &l);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         
         TRACE("bv", 
               tout << mk_pp(lhs, m) << " == \n";
@@ -705,7 +722,9 @@ namespace smt {
             TRACE("bv", tout << mk_pp(lhs, m) << " == " << mk_pp(rhs, m) << "\n";);
             l = literal(mk_eq(lhs, rhs, false));
             ctx.mark_as_relevant(l);
+            if (m.has_trace_stream()) log_axiom_instantiation(ctx.bool_var2expr(l.var()));
             ctx.mk_th_axiom(get_id(), 1, &l);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
             
         }
     }
@@ -1200,8 +1219,10 @@ namespace smt {
 #endif
 
         literal_vector & lits = m_tmp_literals;
+        expr_ref_vector exprs(m);
         lits.reset();
-        lits.push_back(mk_eq(get_enode(v1)->get_owner(), get_enode(v2)->get_owner(), true));
+        literal eq = mk_eq(get_enode(v1)->get_owner(), get_enode(v2)->get_owner(), true);
+        lits.push_back(eq);
         it1 = bits1.begin();
         it2 = bits2.begin();
         for (; it1 != end1; ++it1, ++it2) {
@@ -1212,9 +1233,16 @@ namespace smt {
             ctx.internalize(diff, true);
             literal arg = ctx.get_literal(diff);
             lits.push_back(arg);
+            exprs.push_back(diff);
         }
         m_stats.m_num_diseq_dynamic++;
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(m.mk_not(ctx.bool_var2expr(eq.var())), m.mk_or(exprs.size(), exprs.c_ptr()));
+            log_axiom_instantiation(body);
+        }
         ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     void theory_bv::assign_eh(bool_var v, bool is_true) {
@@ -1306,6 +1334,7 @@ namespace smt {
 
         m_stats.m_num_bit2core++;
         context & ctx = get_context();
+        ast_manager & m = get_manager();
         SASSERT(ctx.get_assignment(antecedent) == l_true);
         SASSERT(m_bits[v2][idx].var() == consequent.var());
         SASSERT(consequent.var() != antecedent.var());
@@ -1322,8 +1351,15 @@ namespace smt {
             literal_vector lits;
             lits.push_back(~consequent);
             lits.push_back(antecedent);
-            lits.push_back(~mk_eq(get_enode(v1)->get_owner(), get_enode(v2)->get_owner(), false));
+            literal eq = mk_eq(get_enode(v1)->get_owner(), get_enode(v2)->get_owner(), false);
+            lits.push_back(~eq);
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(ctx.bool_var2expr(eq.var()), m.mk_implies(ctx.bool_var2expr(consequent.var()), ctx.bool_var2expr(antecedent.var())));
+                log_axiom_instantiation(body);
+            }
             ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
      
             if (m_wpos[v2] == idx)
                 find_wpos(v2);

src/smt/theory_datatype.cpp

@@ -140,7 +140,16 @@ namespace smt {
             args.push_back(acc);
         }
         expr * mk       = m.mk_app(c, args.size(), args.c_ptr());
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_eq(n->get_owner(), mk);
+            if (antecedent != null_literal) {
+                body = m.mk_implies(get_context().bool_var2expr(antecedent.var()), body);
+            }
+            log_axiom_instantiation(body, 1, &n);
+        }
         assert_eq_axiom(n, mk, antecedent);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     /**
@@ -157,11 +166,24 @@ namespace smt {
         func_decl * d     = n->get_decl();
         ptr_vector<func_decl> const & accessors   = *m_util.get_constructor_accessors(d);
         SASSERT(n->get_num_args() == accessors.size());
+        app_ref_vector bindings(m);
+        vector<std::tuple<enode *, enode *>> used_enodes;
+        used_enodes.push_back(std::make_tuple(nullptr, n));
+        for (unsigned i = 0; i < n->get_num_args(); ++i) {
+            bindings.push_back(n->get_arg(i)->get_owner());
+        }
+        unsigned base_id = get_manager().has_trace_stream() && accessors.size() > 0 ? m_util.get_plugin()->get_axiom_base_id(d->get_name()) : 0;
         unsigned i = 0;
         for (func_decl * acc : accessors) {
             app * acc_app     = m.mk_app(acc, n->get_owner());
             enode * arg       = n->get_arg(i);
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_eq(arg->get_owner(), acc_app);
+                log_axiom_instantiation(body, base_id + 3*i, bindings.size(), bindings.c_ptr(), base_id - 3, used_enodes);
+            }
             assert_eq_axiom(arg, acc_app, null_literal);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
             ++i;
         }
     }
@@ -218,10 +240,20 @@ namespace smt {
                 arg = ctx.get_enode(acc_app);
             }
             app * acc_own = m.mk_app(acc1, own);
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(rec_app, m.mk_eq(arg->get_owner(), acc_own));
+                log_axiom_instantiation(body, 1, &n);
+            }
             assert_eq_axiom(arg, acc_own, is_con); 
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         }
         // update_field is identity if 'n' is not created by a matching constructor.        
+        app_ref imp(m);
+        imp = m.mk_implies(m.mk_not(rec_app), m.mk_eq(n->get_owner(), arg1));
+        if (m.has_trace_stream()) log_axiom_instantiation(imp, 1, &n);
         assert_eq_axiom(n, arg1, ~is_con);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     theory_var theory_datatype::mk_var(enode * n) {

src/smt/theory_diff_logic_def.h

@@ -598,7 +598,9 @@ void theory_diff_logic<Ext>::new_edge(dl_var src, dl_var dst, unsigned num_edges
         le = m_util.mk_le(m_util.mk_add(n2,n1), n3);
         le = get_manager().mk_not(le);
     }
+    if (get_manager().has_trace_stream())log_axiom_instantiation(le);
     ctx.internalize(le, false);
+    if (get_manager().has_trace_stream()) get_manager().trace_stream() << "[end-of-instance]\n";
     ctx.mark_as_relevant(le.get());
     literal lit(ctx.get_literal(le));
     bool_var bv = lit.var();
@@ -1007,6 +1009,11 @@ void theory_diff_logic<Ext>::new_eq_or_diseq(bool is_eq, theory_var v1, theory_v
         t2 = m_util.mk_numeral(k, m.get_sort(s2.get()));
         // t1 - s1 = k
         eq = m.mk_eq(s2.get(), t2.get());
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_eq(m.mk_eq(m_util.mk_add(s1, t2), t1), eq);
+            log_axiom_instantiation(body);
+        }
         
         TRACE("diff_logic", 
               tout << v1 << " .. " << v2 << "\n";
@@ -1015,6 +1022,8 @@ void theory_diff_logic<Ext>::new_eq_or_diseq(bool is_eq, theory_var v1, theory_v
         if (!internalize_atom(eq.get(), false)) {
             UNREACHABLE();
         }
+
+        if (m.has_trace_stream()) get_manager().trace_stream() << "[end-of-instance]\n";
                 
         literal l(ctx.get_literal(eq.get()));
         if (!is_eq) {

src/smt/theory_dl.cpp

@@ -256,6 +256,11 @@ namespace smt {
             lt = u().mk_lt(x,y);
             le = b().mk_ule(m().mk_app(r,y),m().mk_app(r,x)); 
             context& ctx = get_context();
+            if (m().has_trace_stream()) {
+                app_ref body(m());
+                body = m().mk_eq(lt, le);
+                log_axiom_instantiation(body);
+            }
             ctx.internalize(lt, false);
             ctx.internalize(le, false);
             literal lit1(ctx.get_literal(lt));
@@ -266,12 +271,15 @@ namespace smt {
             literal lits2[2] = { ~lit1, ~lit2 };
             ctx.mk_th_axiom(get_id(), 2, lits1);
             ctx.mk_th_axiom(get_id(), 2, lits2);
+            if (m().has_trace_stream()) m().trace_stream() << "[end-of-instance]\n";
         }
 
         void assert_cnstr(expr* e) {
             TRACE("theory_dl", tout << mk_pp(e, m()) << "\n";);
             context& ctx = get_context();
+            if (m().has_trace_stream()) log_axiom_instantiation(e);
             ctx.internalize(e, false);
+            if (m().has_trace_stream()) m().trace_stream() << "[end-of-instance]\n";
             literal lit(ctx.get_literal(e));
             ctx.mark_as_relevant(lit);
             ctx.mk_th_axiom(get_id(), 1, &lit);

src/smt/theory_fpa.cpp

@@ -409,7 +409,9 @@ namespace smt {
         if (get_manager().is_true(e)) return;
         TRACE("t_fpa_detail", tout << "asserting " << mk_ismt2_pp(e, get_manager()) << "\n";);
         context & ctx = get_context();
+        if (get_manager().has_trace_stream()) log_axiom_instantiation(e);
         ctx.internalize(e, false);
+        if (get_manager().has_trace_stream()) get_manager().trace_stream() << "[end-of-instance]\n";
         literal lit(ctx.get_literal(e));
         ctx.mark_as_relevant(lit);
         ctx.mk_th_axiom(get_id(), 1, &lit);

src/smt/theory_jobscheduler.cpp

@@ -305,6 +305,13 @@ namespace smt {
 
             literal end_ge_lo = mk_ge(ji.m_end, clb);
             // Initialization ensures that satisfiable states have completion time below end.
+            ast_manager& m = get_manager();
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_and(m.mk_eq(eq.first->get_owner(), eq.second->get_owner()), ctx.bool_var2expr(start_ge_lo.var())), ctx.bool_var2expr(end_ge_lo.var()));
+                log_axiom_instantiation(body);
+                m.trace_stream() << "[end-of-instance]\n";
+            }
             region& r = ctx.get_region();
             ctx.assign(end_ge_lo, 
                        ctx.mk_justification(
@@ -379,6 +386,13 @@ namespace smt {
         lits.push_back(mk_eq_lit(end_e->get_owner(), rhs));
         context& ctx = get_context();
         ctx.mk_clause(lits.size(), lits.c_ptr(), nullptr, CLS_AUX_LEMMA, nullptr);
+        ast_manager& m = get_manager();
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(m.mk_and(ctx.bool_var2expr(lits[0].var()), ctx.bool_var2expr(lits[1].var()), ctx.bool_var2expr(lits[2].var())), ctx.bool_var2expr(lits[3].var()));
+            log_axiom_instantiation(body);
+            m.trace_stream() << "[end-of-instance]\n";
+        }
         return true;
     }
 
@@ -736,7 +750,9 @@ namespace smt {
 
             // start(j) <= end(j)            
             lit = mk_le(ji.m_start, ji.m_end);
+            if (m.has_trace_stream()) log_axiom_instantiation(ctx.bool_var2expr(lit.var()));
             ctx.mk_th_axiom(get_id(), 1, &lit);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
 
             time_t start_lb = std::numeric_limits<time_t>::max();
             time_t runtime_lb = std::numeric_limits<time_t>::max();
@@ -779,11 +795,15 @@ namespace smt {
 
             // start(j) >= start_lb
             lit = mk_ge(ji.m_start, start_lb);
+            if (m.has_trace_stream()) log_axiom_instantiation(ctx.bool_var2expr(lit.var()));
             ctx.mk_th_axiom(get_id(), 1, &lit);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
 
             // end(j) <= end_ub
             lit = mk_le(ji.m_end, end_ub);
+            if (m.has_trace_stream()) log_axiom_instantiation(ctx.bool_var2expr(lit.var()));
             ctx.mk_th_axiom(get_id(), 1, &lit);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
 
             // start(j) + runtime_lb <= end(j)
             // end(j) <= start(j) + runtime_ub 
@@ -799,7 +819,14 @@ namespace smt {
 #if 0
         job_info const& ji = m_jobs[j];
         literal l2 = mk_le(ji.m_end, jr.m_finite_capacity_end);
-        get_context().mk_th_axiom(get_id(), ~eq, l2);
+        context& ctx = get_context();
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(ctx.bool_var2expr(eq.var()), ctx.bool_var2expr(l2.var()));
+            log_axiom_instantiation(body);
+        }
+        ctx.mk_th_axiom(get_id(), ~eq, l2);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
 #endif
     }
 
@@ -808,11 +835,24 @@ namespace smt {
         context& ctx = get_context();
         time_t t;
         if (lst(j, r, t)) {
-            ctx.mk_th_axiom(get_id(), ~eq, mk_le(m_jobs[j].m_start, t));
+            literal le = mk_le(m_jobs[j].m_start, t);
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(ctx.bool_var2expr(eq.var()), ctx.bool_var2expr(le.var()));
+                log_axiom_instantiation(body);
+            }
+            ctx.mk_th_axiom(get_id(), ~eq, le);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         }
         else {
             eq.neg();
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_not(ctx.bool_var2expr(eq.var()));
+                log_axiom_instantiation(body);
+            }
             ctx.mk_th_axiom(get_id(), 1, &eq);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         }
     }
 
@@ -823,7 +863,14 @@ namespace smt {
         if (!first_available(jr, m_resources[r], idx)) return;
         vector<res_available>& available = m_resources[r].m_available;
         literal l2 = mk_ge(m_jobs[j].m_start, available[idx].m_start);
-        get_context().mk_th_axiom(get_id(), ~eq, l2);
+        context& ctx = get_context();
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(ctx.bool_var2expr(eq.var()), ctx.bool_var2expr(l2.var()));
+            log_axiom_instantiation(body);
+        }
+        ctx.mk_th_axiom(get_id(), ~eq, l2);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     // resource(j) = r => start(j) <= end[idx]  || start[idx+1] <= start(j);
@@ -834,7 +881,14 @@ namespace smt {
         SASSERT(resource_available(jr, available[idx]));
         literal l2 = mk_ge(m_jobs[j].m_start, available[idx1].m_start);
         literal l3 = mk_le(m_jobs[j].m_start, available[idx].m_end);
-        get_context().mk_th_axiom(get_id(), ~eq, l2, l3);        
+        context& ctx = get_context();
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(ctx.bool_var2expr(eq.var()), m.mk_or(ctx.bool_var2expr(l2.var()), ctx.bool_var2expr(l3.var())));
+            log_axiom_instantiation(body);
+        }
+        ctx.mk_th_axiom(get_id(), ~eq, l2, l3);        
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     // resource(j) = r => end(j) <= end[idx] || start[idx+1] <= start(j);
@@ -845,7 +899,14 @@ namespace smt {
         SASSERT(resource_available(jr, available[idx]));
         literal l2 = mk_le(m_jobs[j].m_end, available[idx].m_end);
         literal l3 = mk_ge(m_jobs[j].m_start, available[idx1].m_start);
-        get_context().mk_th_axiom(get_id(), ~eq, l2, l3);
+        context& ctx = get_context();
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(ctx.bool_var2expr(eq.var()), m.mk_or(ctx.bool_var2expr(l2.var()), ctx.bool_var2expr(l3.var())));
+            log_axiom_instantiation(body);
+        }
+        ctx.mk_th_axiom(get_id(), ~eq, l2, l3);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }    
 
     /**
@@ -864,6 +925,12 @@ namespace smt {
             if (ctx.is_diseq(e1, e2))
                 continue;
             literal eq = mk_eq_lit(e1, e2);
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_or(ctx.bool_var2expr(eq.var()), m.mk_not(ctx.bool_var2expr(eq.var())));
+                log_axiom_instantiation(body);
+                m.trace_stream() << "[end-of-instance]\n";
+            }
             if (ctx.get_assignment(eq) != l_false) {
                 ctx.mark_as_relevant(eq);
                 if (assume_eq(e1, e2)) {
@@ -872,14 +939,23 @@ namespace smt {
             }
         }
         literal_vector lits;
+        expr_ref_vector exprs(m);
         for (job_resource const& jr : jrs) {
             unsigned r = jr.m_resource_id;
             res_info const& ri = m_resources[r];
             enode* e1 = ji.m_job2resource;
             enode* e2 = ri.m_resource;
-            lits.push_back(mk_eq_lit(e1, e2));
+            literal eq = mk_eq_lit(e1, e2);
+            lits.push_back(eq);
+            exprs.push_back(ctx.bool_var2expr(eq.var()));
+        }
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_or(exprs.size(), exprs.c_ptr());
+            log_axiom_instantiation(body);
         }
         ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         return true;
     }
 

src/smt/theory_lra.cpp

@@ -1026,9 +1026,18 @@ public:
         expr_ref rem(a.mk_rem(dividend, divisor), m);
         expr_ref mod(a.mk_mod(dividend, divisor), m);
         expr_ref mmod(a.mk_uminus(mod), m);
-        literal dgez = mk_literal(a.mk_ge(divisor, zero));
-        mk_axiom(~dgez, th.mk_eq(rem, mod,  false));
-        mk_axiom( dgez, th.mk_eq(rem, mmod, false));                    
+        expr_ref degz_expr(a.mk_ge(divisor, zero), m);
+        literal dgez = mk_literal(degz_expr);
+        literal pos = th.mk_eq(rem, mod,  false);
+        literal neg = th.mk_eq(rem, mmod, false);
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_ite(degz_expr, ctx().bool_var2expr(pos.var()), ctx().bool_var2expr(neg.var()));
+            th.log_axiom_instantiation(body);
+        }
+        mk_axiom(~dgez, pos);
+        mk_axiom( dgez, neg);                    
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     // q = 0 or q * (p div q) = p
@@ -1036,7 +1045,13 @@ public:
         if (a.is_zero(q)) return;
         literal eqz = th.mk_eq(q, a.mk_real(0), false);
         literal eq  = th.mk_eq(a.mk_mul(q, a.mk_div(p, q)), p, false);
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(m.mk_not(ctx().bool_var2expr(eqz.var())), ctx().bool_var2expr(eq.var()));
+            th.log_axiom_instantiation(body);
+        }
         mk_axiom(eqz, eq);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     // to_int (to_real x) = x
@@ -1045,14 +1060,28 @@ public:
         expr* x = nullptr, *y = nullptr;
         VERIFY (a.is_to_int(n, x));            
         if (a.is_to_real(x, y)) {
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_eq(n, y);
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(th.mk_eq(y, n, false));
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         }
         else {
             expr_ref to_r(a.mk_to_real(n), m);
             expr_ref lo(a.mk_le(a.mk_sub(to_r, x), a.mk_real(0)), m);
             expr_ref hi(a.mk_ge(a.mk_sub(x, to_r), a.mk_real(1)), m);
+            if (m.has_trace_stream()) th.log_axiom_instantiation(lo);
             mk_axiom(mk_literal(lo));
+            if (m.has_trace_stream()) {
+                m.trace_stream() << "[end-of-instance]\n";
+                expr_ref body(m);
+                body = m.mk_not(hi);
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(~mk_literal(hi));
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         }
     }
 
@@ -1062,8 +1091,14 @@ public:
         VERIFY(a.is_is_int(n, x));
         literal eq = th.mk_eq(a.mk_to_real(a.mk_to_int(x)), x, false);
         literal is_int = ctx().get_literal(n);
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_iff(n, ctx().bool_var2expr(eq.var()));
+            th.log_axiom_instantiation(body);
+        }
         mk_axiom(~is_int, eq);
         mk_axiom(is_int, ~eq);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     // create axiom for 
@@ -1115,17 +1150,60 @@ public:
             k = rational::zero();
         }
 
+        context& c = ctx();
         if (!k.is_zero()) {
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_not(m.mk_eq(q, zero)), c.bool_var2expr(eq.var()));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(eq);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_not(m.mk_eq(q, zero)), c.bool_var2expr(mod_ge_0.var()));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(mod_ge_0);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_not(m.mk_eq(q, zero)), a.mk_le(mod, upper));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(mk_literal(a.mk_le(mod, upper)));
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
             if (k.is_pos()) {
+                if (m.has_trace_stream()) {
+                    app_ref body(m);
+                    body = m.mk_implies(m.mk_and(a.mk_gt(q, zero), c.bool_var2expr(p_ge_0.var())), c.bool_var2expr(div_ge_0.var()));
+                    th.log_axiom_instantiation(body);
+                }
                 mk_axiom(~p_ge_0, div_ge_0);
+                if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+                if (m.has_trace_stream()) {
+                    app_ref body(m);
+                    body = m.mk_implies(m.mk_and(a.mk_gt(q, zero), c.bool_var2expr(p_le_0.var())), c.bool_var2expr(div_le_0.var()));
+                    th.log_axiom_instantiation(body);
+                }
                 mk_axiom(~p_le_0, div_le_0);
+                if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
             }
             else {
+                if (m.has_trace_stream()) {
+                    app_ref body(m);
+                    body = m.mk_implies(m.mk_and(a.mk_lt(q, zero), c.bool_var2expr(p_ge_0.var())), c.bool_var2expr(div_le_0.var()));
+                    th.log_axiom_instantiation(body);
+                }
                 mk_axiom(~p_ge_0, div_le_0);
+                if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+                if (m.has_trace_stream()) {
+                    app_ref body(m);
+                    body = m.mk_implies(m.mk_and(a.mk_lt(q, zero), c.bool_var2expr(p_le_0.var())), c.bool_var2expr(div_ge_0.var()));
+                    th.log_axiom_instantiation(body);
+                }
                 mk_axiom(~p_le_0, div_ge_0);
+                if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
             }
         }
         else {
@@ -1137,26 +1215,82 @@ public:
             // q >= 0 or (p mod q) < -q
             literal q_ge_0 = mk_literal(a.mk_ge(q, zero));
             literal q_le_0 = mk_literal(a.mk_le(q, zero));
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_not(m.mk_eq(q, zero)), c.bool_var2expr(eq.var()));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(q_ge_0, eq);
             mk_axiom(q_le_0, eq);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_not(m.mk_eq(q, zero)), c.bool_var2expr(mod_ge_0.var()));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(q_ge_0, mod_ge_0);
             mk_axiom(q_le_0, mod_ge_0);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(a.mk_lt(q, zero), a.mk_lt(a.mk_sub(mod, q), zero));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(q_le_0, ~mk_literal(a.mk_ge(a.mk_sub(mod, q), zero)));
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(a.mk_lt(q, zero), a.mk_lt(a.mk_add(mod, q), zero));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(q_ge_0, ~mk_literal(a.mk_ge(a.mk_add(mod, q), zero)));        
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_and(a.mk_gt(q, zero), c.bool_var2expr(p_ge_0.var())), c.bool_var2expr(div_ge_0.var()));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(q_le_0, ~p_ge_0, div_ge_0); 
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_and(a.mk_gt(q, zero), c.bool_var2expr(p_le_0.var())), c.bool_var2expr(div_le_0.var()));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(q_le_0, ~p_le_0, div_le_0); 
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_and(a.mk_lt(q, zero), c.bool_var2expr(p_ge_0.var())), c.bool_var2expr(div_le_0.var()));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(q_ge_0, ~p_ge_0, div_le_0); 
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_and(a.mk_lt(q, zero), c.bool_var2expr(p_le_0.var())), c.bool_var2expr(div_ge_0.var()));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(q_ge_0, ~p_le_0, div_ge_0); 
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         }
         if (m_arith_params.m_arith_enum_const_mod && k.is_pos() && k < rational(8)) {
             unsigned _k = k.get_unsigned();
             literal_buffer lits;
+            expr_ref_vector exprs(m);
             for (unsigned j = 0; j < _k; ++j) {
                 literal mod_j = th.mk_eq(mod, a.mk_int(j), false);
                 lits.push_back(mod_j);
+                exprs.push_back(c.bool_var2expr(mod_j.var()));
                 ctx().mark_as_relevant(mod_j);
             }
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_or(exprs.size(), exprs.c_ptr());
+                th.log_axiom_instantiation(body);
+            }
             ctx().mk_th_axiom(get_id(), lits.size(), lits.begin());                
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         }            
     }
 
@@ -1591,8 +1725,20 @@ public:
                 literal p_ge_r1  = mk_literal(a.mk_ge(p, a.mk_numeral(lo, true)));
                 literal n_le_div = mk_literal(a.mk_le(n, a.mk_numeral(div_r, true)));
                 literal n_ge_div = mk_literal(a.mk_ge(n, a.mk_numeral(div_r, true)));
+                if (m.has_trace_stream()) {
+                    app_ref body(m);
+                    body = m.mk_implies(ctx().bool_var2expr(p_le_r1.var()), ctx().bool_var2expr(n_le_div.var()));
+                    th.log_axiom_instantiation(body);
+                }
                 mk_axiom(~p_le_r1, n_le_div); 
+                if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+                if (m.has_trace_stream()) {
+                    app_ref body(m);
+                    body = m.mk_implies(ctx().bool_var2expr(p_ge_r1.var()), ctx().bool_var2expr(n_ge_div.var()));
+                    th.log_axiom_instantiation(body);
+                }
                 mk_axiom(~p_ge_r1, n_ge_div);
+                if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
 
                 all_divs_valid = false;
 
@@ -1631,8 +1777,20 @@ public:
             literal pq_rhs   = ~mk_literal(a.mk_ge(pqr, zero));
             literal n_le_div = mk_literal(a.mk_le(n, divc));
             literal n_ge_div = mk_literal(a.mk_ge(n, divc)); 
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(ctx().bool_var2expr(pq_lhs.var()), ctx().bool_var2expr(n_le_div.var()));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(pq_lhs, n_le_div); 
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(ctx().bool_var2expr(pq_rhs.var()), ctx().bool_var2expr(n_ge_div.var()));
+                th.log_axiom_instantiation(body);
+            }
             mk_axiom(pq_rhs, n_ge_div);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
             TRACE("arith",
                   literal_vector lits;
                   lits.push_back(pq_lhs);
@@ -1747,6 +1905,12 @@ public:
         case lp::lia_move::branch: {
             TRACE("arith", tout << "branch\n";);
             app_ref b = mk_bound(m_lia->get_term(), m_lia->get_offset(), !m_lia->is_upper());
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_or(b, m.mk_not(b));
+                th.log_axiom_instantiation(body);
+                m.trace_stream() << "[end-of-instance]\n";
+            }
             IF_VERBOSE(2, verbose_stream() << "branch " << b << "\n";);
             // branch on term >= k + 1
             // branch on term <= k
@@ -1760,6 +1924,10 @@ public:
             ++m_stats.m_gomory_cuts;
             // m_explanation implies term <= k
             app_ref b = mk_bound(m_lia->get_term(), m_lia->get_offset(), !m_lia->is_upper());
+            if (m.has_trace_stream()) {
+                th.log_axiom_instantiation(b);
+                m.trace_stream() << "[end-of-instance]\n";
+            }
             IF_VERBOSE(2, verbose_stream() << "cut " << b << "\n");
             TRACE("arith", dump_cut_lemma(tout, m_lia->get_term(), m_lia->get_offset(), m_lia->get_explanation(), m_lia->is_upper()););
             m_eqs.reset();

src/smt/theory_recfun.cpp

@@ -308,7 +308,9 @@ namespace smt {
         unsigned depth = get_depth(e.m_lhs);
         expr_ref rhs(apply_args(depth, vars, e.m_args, e.m_def->get_rhs()), m);
         literal lit = mk_eq_lit(lhs, rhs);
+        if (m.has_trace_stream()) log_axiom_instantiation(ctx().bool_var2expr(lit.var()));
         ctx().mk_th_axiom(get_id(), 1, &lit);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         TRACEFN("macro expansion yields " << mk_pp(rhs, m) << "\n" <<
                 "literal                " << pp_lit(ctx(), lit));
     }
@@ -327,6 +329,7 @@ namespace smt {
         // add case-axioms for all case-paths
         auto & vars = e.m_def->get_vars();
         literal_vector preds;
+        expr_ref_vector pred_exprs(m);
         for (recfun::case_def const & c : e.m_def->get_cases()) {
             // applied predicate to `args`
             app_ref pred_applied = c.apply_case_predicate(e.m_args);
@@ -337,6 +340,7 @@ namespace smt {
             SASSERT(u().owns_app(pred_applied));
             literal concl = mk_literal(pred_applied);
             preds.push_back(concl);
+            pred_exprs.push_back(pred_applied);
 
             if (c.is_immediate()) {
                 body_expansion be(pred_applied, c, e.m_args);
@@ -348,20 +352,39 @@ namespace smt {
             }
 
             literal_vector guards;
+            expr_ref_vector exprs(m);
             guards.push_back(concl);
             for (auto & g : c.get_guards()) {
                 expr_ref ga = apply_args(depth, vars, e.m_args, g);
                 literal guard = mk_literal(ga);
                 guards.push_back(~guard);
+                exprs.push_back(m.mk_not(ga));
                 literal c[2] = {~concl, guard};
+                if (m.has_trace_stream()) {
+                    app_ref body(m);
+                    body = m.mk_implies(pred_applied, ga);
+                    log_axiom_instantiation(body);
+                }
                 ctx().mk_th_axiom(get_id(), 2, c);
+                if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
+            }
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(m.mk_not(pred_applied), m.mk_or(exprs.size(), exprs.c_ptr()));
+                log_axiom_instantiation(body);
             }
             ctx().mk_th_axiom(get_id(), guards);
-
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         }
         // the disjunction of branches is asserted
         // to close the available cases. 
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_or(pred_exprs.size(), pred_exprs.c_ptr());
+            log_axiom_instantiation(body);
+        }
         ctx().mk_th_axiom(get_id(), preds);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 
     /**
@@ -382,9 +405,11 @@ namespace smt {
         expr_ref rhs = apply_args(depth, vars, args, e.m_cdef->get_rhs());
 
         literal_vector clause;
+        expr_ref_vector exprs(m);
         for (auto & g : e.m_cdef->get_guards()) {
             expr_ref guard = apply_args(depth, vars, args, g);
             clause.push_back(~mk_literal(guard));
+            exprs.push_back(guard);
             if (clause.back() == true_literal) {
                 TRACEFN("body " << pp_body_expansion(e,m) << "\n" << clause << "\n" << guard);
                 return;
@@ -394,7 +419,13 @@ namespace smt {
             }
         }        
         clause.push_back(mk_eq_lit(lhs, rhs));
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(m.mk_and(exprs.size(), exprs.c_ptr()), m.mk_eq(lhs, rhs));
+            log_axiom_instantiation(body);
+        }
         ctx().mk_th_axiom(get_id(), clause);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         TRACEFN("body   " << pp_body_expansion(e,m));
         TRACEFN(pp_lits(ctx(), clause));
     }

src/smt/theory_seq.cpp

@@ -2166,6 +2166,13 @@ void theory_seq::propagate_lit(dependency* dep, unsigned n, literal const* _lits
 
     m_new_propagation = true;
     ctx.assign(lit, js);    
+    if (m.has_trace_stream()) {
+        expr_ref expr(m);
+        expr = ctx.bool_var2expr(lit.var());
+        if (lit.sign()) expr = m.mk_not(expr);
+        log_axiom_instantiation(expr);
+        m.trace_stream() << "[end-of-instance]\n";
+    }
 }
 
 void theory_seq::set_conflict(dependency* dep, literal_vector const& _lits) {
@@ -2199,7 +2206,13 @@ void theory_seq::propagate_eq(dependency* dep, enode* n1, enode* n2) {
     justification* js = ctx.mk_justification(
         ext_theory_eq_propagation_justification(
             get_id(), ctx.get_region(), lits.size(), lits.c_ptr(), eqs.size(), eqs.c_ptr(), n1, n2));
+    if (m.has_trace_stream()) {
+        app_ref body(m);
+        body = m.mk_eq(n1->get_owner(), n2->get_owner());
+        log_axiom_instantiation(body);
+    }
     ctx.assign_eq(n1, n2, eq_justification(js));
+    if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     m_new_propagation = true;
 
     enforce_length_coherence(n1, n2);
@@ -3172,6 +3185,18 @@ bool theory_seq::solve_nc(unsigned idx) {
         }
         TRACE("seq", ctx.display_literals_verbose(tout, lits.size(), lits.c_ptr()) << "\n";);
         ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
+        if (m.has_trace_stream()) {
+            expr_ref_vector exprs(m);
+            for (literal l : lits) {
+                expr* e = ctx.bool_var2expr(l.var());
+                if (l.sign()) e = m.mk_not(e);
+                exprs.push_back(e);
+            }
+            app_ref body(m);
+            body = m.mk_or(exprs.size(), exprs.c_ptr());
+            log_axiom_instantiation(body);
+            m.trace_stream() << "[end-of-instance]\n";
+        }
         return true;
     }
     
@@ -4617,16 +4642,25 @@ void theory_seq::propagate_in_re(expr* n, bool is_true) {
     unsigned_vector states;
     a->get_epsilon_closure(a->init(), states);
     lits.push_back(~lit);
+    expr_ref_vector exprs(m);
     
     for (unsigned st : states) {
-        lits.push_back(mk_accept(s, zero, re, st));
+        literal acc = mk_accept(s, zero, re, st);
+        lits.push_back(acc);
+        exprs.push_back(ctx.bool_var2expr(acc.var()));
     }
     if (lits.size() == 2) {
         propagate_lit(nullptr, 1, &lit, lits[1]);
     }
     else {
         TRACE("seq", ctx.display_literals_verbose(tout, lits) << "\n";);
+        if (m.has_trace_stream()) {
+            app_ref body(m);
+            body = m.mk_implies(n, m.mk_or(exprs.size(), exprs.c_ptr()));
+            log_axiom_instantiation(body);
+        }
         ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
     }
 }
 
@@ -5071,19 +5105,32 @@ literal theory_seq::mk_eq_empty(expr* _e, bool phase) {
     return lit;
 }
 
+void theory_seq::push_lit_as_expr(literal l, expr_ref_vector& buf) {
+    expr* e = get_context().bool_var2expr(l.var());
+    if (l.sign()) e = m.mk_not(e);
+    buf.push_back(e);
+}
+
 void theory_seq::add_axiom(literal l1, literal l2, literal l3, literal l4, literal l5) {
     context& ctx = get_context();
     literal_vector lits;
+    expr_ref_vector exprs(m);
     if (l1 == true_literal || l2 == true_literal || l3 == true_literal || l4 == true_literal || l5 == true_literal) return;
-    if (l1 != null_literal && l1 != false_literal) { ctx.mark_as_relevant(l1); lits.push_back(l1); }
-    if (l2 != null_literal && l2 != false_literal) { ctx.mark_as_relevant(l2); lits.push_back(l2); }
-    if (l3 != null_literal && l3 != false_literal) { ctx.mark_as_relevant(l3); lits.push_back(l3); }
-    if (l4 != null_literal && l4 != false_literal) { ctx.mark_as_relevant(l4); lits.push_back(l4); }
-    if (l5 != null_literal && l5 != false_literal) { ctx.mark_as_relevant(l5); lits.push_back(l5); }
+    if (l1 != null_literal && l1 != false_literal) { ctx.mark_as_relevant(l1); lits.push_back(l1); push_lit_as_expr(l1, exprs); }
+    if (l2 != null_literal && l2 != false_literal) { ctx.mark_as_relevant(l2); lits.push_back(l2); push_lit_as_expr(l2, exprs); }
+    if (l3 != null_literal && l3 != false_literal) { ctx.mark_as_relevant(l3); lits.push_back(l3); push_lit_as_expr(l3, exprs); }
+    if (l4 != null_literal && l4 != false_literal) { ctx.mark_as_relevant(l4); lits.push_back(l4); push_lit_as_expr(l4, exprs); }
+    if (l5 != null_literal && l5 != false_literal) { ctx.mark_as_relevant(l5); lits.push_back(l5); push_lit_as_expr(l5, exprs); }
     TRACE("seq", ctx.display_literals_verbose(tout << "assert:\n", lits) << "\n";);
     m_new_propagation = true;
     ++m_stats.m_add_axiom;
+    if (m.has_trace_stream()) {
+        app_ref body(m);
+        body = m.mk_or(exprs.size(), exprs.c_ptr());
+        log_axiom_instantiation(body);
+    }
     ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
+    if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
 }
 
 
@@ -5208,7 +5255,13 @@ void theory_seq::propagate_eq(dependency* deps, literal_vector const& _lits, exp
                 get_id(), ctx.get_region(), lits.size(), lits.c_ptr(), eqs.size(), eqs.c_ptr(), n1, n2));
 
     m_new_propagation = true;
+    if (m.has_trace_stream()) {
+        app_ref body(m);
+        body = m.mk_eq(e1, e2);
+        log_axiom_instantiation(body);
+    }
     ctx.assign_eq(n1, n2, eq_justification(js));
+    if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
 }
 
 
@@ -5254,7 +5307,13 @@ void theory_seq::assign_eh(bool_var v, bool is_true) {
                 lits.push_back(mk_literal(d));
             }
             ++m_stats.m_add_axiom;            
+            if (m.has_trace_stream()) {
+                app_ref body(m);
+                body = m.mk_implies(e, m.mk_or(disj.size(), disj.c_ptr()));
+                log_axiom_instantiation(body);
+            }
             ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
             for (expr* d : disj) {
                 add_axiom(lit, ~mk_literal(d));
             }
@@ -5613,14 +5672,23 @@ void theory_seq::propagate_accept(literal lit, expr* acc) {
     eautomaton::moves mvs;
     aut->get_moves_from(src, mvs);
     TRACE("seq", tout << mk_pp(acc, m) << " #moves " << mvs.size() << "\n";);
+    expr_ref_vector exprs(m);
     for (auto const& mv : mvs) {
         expr_ref nth = mk_nth(e, idx);
         expr_ref t = mv.t()->accept(nth);
-        ctx.get_rewriter()(t);
-        literal step = mk_literal(mk_step(e, idx, re, src, mv.dst(), t));
+        get_context().get_rewriter()(t);
+        expr_ref step_e(mk_step(e, idx, re, src, mv.dst(), t), m);
+        literal step = mk_literal(step_e);
         lits.push_back(step);
+        exprs.push_back(step_e);
+    }
+    if (m.has_trace_stream()) {
+        app_ref body(m);
+        body = m.mk_implies(acc, m.mk_or(exprs.size(), exprs.c_ptr()));
+        log_axiom_instantiation(body);
     }
     ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
+    if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
 
     if (_idx.get_unsigned() > m_max_unfolding_depth && 
         m_max_unfolding_lit != null_literal && ctx.get_scope_level() > 0) {

src/smt/theory_seq.h

@@ -547,6 +547,7 @@ namespace smt {
         // terms whose meaning are encoded using axioms.
         void enque_axiom(expr* e);
         void deque_axiom(expr* e);
+        void push_lit_as_expr(literal l, expr_ref_vector& buf);
         void add_axiom(literal l1, literal l2 = null_literal, literal l3 = null_literal, literal l4 = null_literal, literal l5 = null_literal);        
         void add_indexof_axiom(expr* e);
         void add_replace_axiom(expr* e);

src/smt/theory_str.cpp

@@ -217,7 +217,9 @@ namespace smt {
         }
         literal lit(ctx.get_literal(e));
         ctx.mark_as_relevant(lit);
+        if (m.has_trace_stream()) log_axiom_instantiation(e);
         ctx.mk_th_axiom(get_id(), 1, &lit);
+        if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
 
         // crash/error avoidance: add all axioms to the trail
         m_trail.push_back(e);
@@ -1084,7 +1086,9 @@ namespace smt {
 
             literal lit(mk_eq(len_str, len, false));
             ctx.mark_as_relevant(lit);
+            if (m.has_trace_stream()) log_axiom_instantiation(ctx.bool_var2expr(lit.var()));
             ctx.mk_th_axiom(get_id(), 1, &lit);
+            if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
         } else {
             // build axiom 1: Length(a_str) >= 0
             {
@@ -1126,7 +1130,9 @@ namespace smt {
                 TRACE("str", tout << "string axiom 2: " << mk_ismt2_pp(lhs, m) << " <=> " << mk_ismt2_pp(rhs, m) << std::endl;);
                 literal l(mk_eq(lhs, rhs, true));
                 ctx.mark_as_relevant(l);
+                if (m.has_trace_stream()) log_axiom_instantiation(ctx.bool_var2expr(l.var()));
                 ctx.mk_th_axiom(get_id(), 1, &l);
+                if (m.has_trace_stream()) m.trace_stream() << "[end-of-instance]\n";
             }
 
         }

src/util/mpz.cpp

@@ -16,7 +16,8 @@ Author:
 Revision History:
 
 --*/
-#include<sstream>
+#include <sstream>
+#include <iomanip>
 #include "util/mpz.h"
 #include "util/buffer.h"
 #include "util/trace.h"
@@ -1725,6 +1726,101 @@ void mpz_manager<SYNCH>::display_smt2(std::ostream & out, mpz const & a, bool de
     }
 }
 
+template<bool SYNCH>
+void mpz_manager<SYNCH>::display_hex(std::ostream & out, mpz const & a, unsigned num_bits) const {
+    SASSERT(num_bits % 4 == 0);
+    std::ios fmt(nullptr);
+    fmt.copyfmt(out);
+    out << std::hex;
+    if (is_small(a)) {
+        out << std::setw(num_bits/4) << std::setfill('0') << get_uint64(a);
+    } else {
+#ifndef _MP_GMP
+        digit_t *ds = digits(a);
+        unsigned sz = size(a);
+        unsigned bitSize = sz * sizeof(digit_t) * 8;
+        unsigned firstDigitSize;
+        if (num_bits >= bitSize) {
+            firstDigitSize = sizeof(digit_t) * 2;
+
+            for (unsigned i = 0; i < (num_bits - bitSize)/4; ++i) {
+                out << "0";
+            }
+        } else {
+            firstDigitSize = num_bits % (sizeof(digit_t) * 8) / 4;
+        }
+
+        out << std::setfill('0') << std::setw(firstDigitSize) << ds[sz-1] << std::setw(sizeof(digit_t)*2);
+        for (unsigned i = 1; i < sz; ++i) {
+            out << ds[sz-i-1];
+        }
+#else
+        // GMP version
+        size_t sz = mpz_sizeinbase(*(a.m_ptr), 16);
+        unsigned requiredLength = num_bits / 4;
+        unsigned padding = requiredLength > sz ? requiredLength - sz : 0;
+        sbuffer<char, 1024> buffer(sz, 0);
+        mpz_get_str(buffer.c_ptr(), 16, *(a.m_ptr));
+        for (unsigned i = 0; i < padding; ++i) {
+            out << "0";
+        }
+        out << buffer.c_ptr() + (sz > requiredLength ? sz - requiredLength : 0);
+#endif
+    }
+    out.copyfmt(fmt);
+}
+
+void display_binary_data(std::ostream &out, unsigned val, unsigned numBits) {
+    SASSERT(numBits <= sizeof(unsigned)*8);
+    for (int shift = numBits-1; shift >= 0; --shift) {
+        if (val & (1 << shift)) {
+            out << "1";
+        } else {
+            out << "0";
+        }
+    }
+ }
+
+template<bool SYNCH>
+void mpz_manager<SYNCH>::display_bin(std::ostream & out, mpz const & a, unsigned num_bits) const {
+    if (is_small(a)) {
+        display_binary_data(out, get_uint64(a), num_bits);
+    } else {
+#ifndef _MP_GMP
+        digit_t *ds = digits(a);
+        unsigned sz = size(a);
+        const unsigned digitBitSize = sizeof(digit_t) * 8;
+        unsigned bitSize = sz * digitBitSize;
+        unsigned firstDigitLength;
+        if (num_bits > bitSize) {
+            firstDigitLength = 0;
+            for (unsigned i = 0; i < (num_bits - bitSize); ++i) {
+                out << "0";
+            }
+        } else {
+            firstDigitLength = num_bits % digitBitSize;
+        }
+        for (unsigned i = 0; i < sz; ++i) {
+            if (i == 0 && firstDigitLength != 0) {
+                display_binary_data(out, ds[sz-1], firstDigitLength);
+            } else {
+                display_binary_data(out, ds[sz-i-1], digitBitSize);
+            }
+        }
+#else
+        // GMP version
+        size_t sz = mpz_sizeinbase(*(a.m_ptr), 2);
+        unsigned padding = num_bits > sz ? num_bits - sz : 0;
+        sbuffer<char, 1024> buffer(sz, 0);
+        mpz_get_str(buffer.c_ptr(), 2, *(a.m_ptr));
+        for (unsigned i = 0; i < padding; ++i) {
+            out << "0";
+        }
+        out << buffer.c_ptr() + (sz > num_bits ? sz - num_bits : 0);
+#endif
+    }
+}
+
 template<bool SYNCH>
 std::string mpz_manager<SYNCH>::to_string(mpz const & a) const {
     std::ostringstream buffer;

src/util/mpz.h

@@ -592,6 +592,17 @@ public:
     */
     void display_smt2(std::ostream & out, mpz const & a, bool decimal) const;
 
+    /**
+       \brief Displays the num_bits least significant bits of a mpz number in hexadecimal format.
+       num_bits must be divisible by 4.
+    */
+    void display_hex(std::ostream & out, mpz const & a, unsigned num_bits) const;
+
+    /**
+       \brief Displays the num_bits least significant bits of a mpz number in binary format.
+    */
+    void display_bin(std::ostream & out, mpz const & a, unsigned num_bits) const;
+
     static unsigned hash(mpz const & a);
 
     static bool is_one(mpz const & a) {

src/util/rational.h

@@ -93,6 +93,12 @@ public:
     
     void display_decimal(std::ostream & out, unsigned prec, bool truncate = false) const { return m().display_decimal(out, m_val, prec, truncate); }
 
+    void display_smt2(std::ostream & out) const { return m().display_smt2(out, m_val, false); }
+
+    void display_hex(std::ostream & out, unsigned num_bits) const { SASSERT(is_int()); return m().display_hex(out, m_val.numerator(), num_bits); }
+
+    void display_bin(std::ostream & out, unsigned num_bits) const { SASSERT(is_int()); return m().display_bin(out, m_val.numerator(), num_bits); }
+
     bool is_uint64() const { return m().is_uint64(m_val); }
 
     bool is_int64() const { return m().is_int64(m_val); }