remove legacy solve_eqs_tactic entirely

also, bug fixes to elim_unconstrained (elim_uncnstr2) which is to replace legacy tactic for eliminating unconstrained constants.

src/ast/simplifiers/dependent_expr_state.h

@@ -61,9 +61,9 @@ public:
  */
 class dependent_expr_simplifier {
 protected:
-    ast_manager&          m;
+    ast_manager& m;
     dependent_expr_state& m_fmls;
-    trail_stack&          m_trail;
+    trail_stack& m_trail;
     unsigned              m_qhead = 0;          // pointer into last processed formula in m_fmls
 
     unsigned num_scopes() const { return m_trail.get_num_scopes(); }
@@ -78,6 +78,7 @@ public:
     virtual void collect_statistics(statistics& st) const {}
     virtual void reset_statistics() {}
     virtual void updt_params(params_ref const& p) {}
+    virtual void collect_param_descrs(param_descrs& r) {}
 };
 
 /**

src/ast/simplifiers/elim_unconstrained.cpp

@@ -47,11 +47,9 @@ Author:
 
 elim_unconstrained::elim_unconstrained(ast_manager& m, dependent_expr_state& fmls) :
     dependent_expr_simplifier(m, fmls), m_inverter(m), m_lt(*this), m_heap(1024, m_lt), m_trail(m) {
-
     std::function<bool(expr*)> is_var = [&](expr* e) {
-        return is_uninterp_const(e) && !m_frozen.is_marked(e) && get_node(e).m_refcount == 1;
+        return is_uninterp_const(e) && !m_frozen.is_marked(e) && get_node(e).m_refcount <= 1;
     };
-
     m_inverter.set_is_var(is_var);
 }
 
@@ -61,7 +59,6 @@ bool elim_unconstrained::is_var_lt(int v1, int v2) const {
     return n1.m_refcount < n2.m_refcount;
 }
 
-
 void elim_unconstrained::eliminate() {
 
     while (!m_heap.empty()) {
@@ -79,8 +76,7 @@ void elim_unconstrained::eliminate() {
             continue;
         }
         expr* e = get_parent(v);
-        for (expr* p : n.m_parents)
-            IF_VERBOSE(11, verbose_stream() << "parent " << mk_bounded_pp(p, m) << "\n");
+        IF_VERBOSE(11, for (expr* p : n.m_parents) verbose_stream() << "parent " << mk_bounded_pp(p, m) << " @ " << get_node(p).m_refcount << "\n";);
         if (!e || !is_app(e) || !is_ground(e)) {
             n.m_refcount = 0;
             continue;
@@ -90,6 +86,7 @@ void elim_unconstrained::eliminate() {
         for (expr* arg : *to_app(t))
             m_args.push_back(get_node(arg).m_term);
         if (!m_inverter(t->get_decl(), m_args.size(), m_args.data(), r, side_cond)) {
+            IF_VERBOSE(11, verbose_stream() << "not inverted " << mk_bounded_pp(e, m) << "\n");
             n.m_refcount = 0;
             continue;
         }
@@ -103,12 +100,12 @@ void elim_unconstrained::eliminate() {
         m_root.setx(r->get_id(), e->get_id(), UINT_MAX);
         get_node(e).m_term = r;
         get_node(e).m_refcount++;
-        IF_VERBOSE(11, verbose_stream() << mk_pp(e, m) << "\n");
-        SASSERT(!m_heap.contains(e->get_id()));
+        IF_VERBOSE(11, verbose_stream() << mk_bounded_pp(e, m) << "\n");
+        SASSERT(!m_heap.contains(root(e)));
         if (is_uninterp_const(r)) 
-            m_heap.insert(e->get_id());                    
+            m_heap.insert(root(e));                    
 
-        IF_VERBOSE(11, verbose_stream() << mk_pp(n.m_orig, m) << " " << mk_pp(t, m) << " -> " << r << " " << get_node(e).m_refcount << "\n");
+        IF_VERBOSE(11, verbose_stream() << mk_bounded_pp(n.m_orig, m) << " " << mk_bounded_pp(t, m) << " -> " << r << " " << get_node(e).m_refcount << "\n";);
 
         SASSERT(!side_cond && "not implemented to add side conditions\n");
     }
@@ -178,7 +175,7 @@ void elim_unconstrained::init_terms(expr_ref_vector const& terms) {
         n.m_term = e;
         n.m_refcount = 0;
         if (is_uninterp_const(e))
-            m_heap.insert(e->get_id());
+            m_heap.insert(root(e));
         if (is_quantifier(e)) {
             expr* body = to_quantifier(e)->get_expr();
             get_node(body).m_parents.push_back(e);

src/ast/simplifiers/elim_unconstrained.h

@@ -23,9 +23,9 @@ Author:
 class elim_unconstrained : public dependent_expr_simplifier {
 
     struct node {
-        unsigned         m_refcount;
-        expr*            m_term;
-        expr*            m_orig;
+        unsigned         m_refcount = 0;
+        expr*            m_term = nullptr;
+        expr*            m_orig = nullptr;
         ptr_vector<expr> m_parents;
     };
     struct var_lt {
@@ -52,11 +52,12 @@ class elim_unconstrained : public dependent_expr_simplifier {
     bool is_var_lt(int v1, int v2) const;
     node& get_node(unsigned n) { return m_nodes[n]; }
     node const& get_node(unsigned n) const { return m_nodes[n]; }
-    node& get_node(expr* t) { return m_nodes[m_root[t->get_id()]]; }
-    node const& get_node(expr* t) const { return m_nodes[m_root[t->get_id()]]; }
+    node& get_node(expr* t) { return m_nodes[root(t)]; }
+    unsigned root(expr* t) const { return m_root[t->get_id()]; }
+    node const& get_node(expr* t) const { return m_nodes[root(t)]; }
     unsigned get_refcount(expr* t) const { return get_node(t).m_refcount; }
-    void inc_ref(expr* t) { ++get_node(t).m_refcount; if (is_uninterp_const(t)) m_heap.increased(t->get_id()); }
-    void dec_ref(expr* t) { --get_node(t).m_refcount; if (is_uninterp_const(t)) m_heap.decreased(t->get_id()); }
+    void inc_ref(expr* t) { ++get_node(t).m_refcount; if (is_uninterp_const(t)) m_heap.increased(root(t)); }
+    void dec_ref(expr* t) { --get_node(t).m_refcount; if (is_uninterp_const(t)) m_heap.decreased(root(t)); }
     void gc(expr* t);
     expr* get_parent(unsigned n) const;
     void init_terms(expr_ref_vector const& terms);

src/ast/simplifiers/solve_eqs.cpp

@@ -240,6 +240,13 @@ namespace euf {
             ex->updt_params(p);
     }
 
+    void solve_eqs::collect_param_descrs(param_descrs& r) {
+        r.insert("solve_eqs_max_occs", CPK_UINT, "(default: infty) maximum number of occurrences for considering a variable for gaussian eliminations.");
+        r.insert("theory_solver", CPK_BOOL, "(default: true) use theory solvers.");
+        r.insert("ite_solver", CPK_BOOL, "(default: true) use if-then-else solver.");
+        r.insert("context_solve", CPK_BOOL, "(default: false) solve equalities under disjunctions.");
+    }
+
     void solve_eqs::collect_statistics(statistics& st) const {
         st.update("solve-eqs-steps", m_stats.m_num_steps);
         st.update("solve-eqs-elim-vars", m_stats.m_num_elim_vars);

src/ast/simplifiers/solve_eqs.h

@@ -72,6 +72,8 @@ namespace euf {
 
         void updt_params(params_ref const& p) override;
 
+        void collect_param_descrs(param_descrs& r) override;
+
         void collect_statistics(statistics& st) const override;
 
     };

src/nlsat/tactic/qfnra_nlsat_tactic.cpp

@@ -27,7 +27,6 @@ Notes:
 #include "tactic/core/elim_uncnstr_tactic.h"
 #include "tactic/core/propagate_values_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/elim_term_ite_tactic.h"
 
 tactic * mk_qfnra_nlsat_tactic(ast_manager & m, params_ref const & p) {

src/opt/opt_context.cpp

@@ -31,7 +31,6 @@ Notes:
 #include "tactic/tactic.h"
 #include "tactic/arith/lia2card_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/simplify_tactic.h"
 #include "tactic/core/propagate_values_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"

src/tactic/core/CMakeLists.txt

@@ -18,7 +18,6 @@ z3_add_component(core_tactics
     propagate_values_tactic.cpp
     reduce_args_tactic.cpp
     simplify_tactic.cpp
-    solve_eqs_tactic.cpp
     special_relations_tactic.cpp
     split_clause_tactic.cpp
     symmetry_reduce_tactic.cpp
@@ -48,7 +47,6 @@ z3_add_component(core_tactics
     reduce_args_tactic.h
     simplify_tactic.h
     solve_eqs_tactic.h
-    solve_eqs2_tactic.h
     special_relations_tactic.h
     split_clause_tactic.h
     symmetry_reduce_tactic.h

src/tactic/core/elim_uncnstr2_tactic.h

@@ -30,7 +30,7 @@ public:
 };
 
 inline tactic * mk_elim_uncnstr2_tactic(ast_manager & m, params_ref const & p = params_ref()) {
-    return alloc(dependent_expr_state_tactic, m, p, alloc(elim_uncnstr2_tactic_factory), "elim-unconstr2");
+    return alloc(dependent_expr_state_tactic, m, p, alloc(elim_uncnstr2_tactic_factory), "elim-uncnstr2");
 }
 
 

src/tactic/core/solve_eqs2_tactic.h

@@ -1,47 +0,0 @@
-/*++
-Copyright (c) 2022 Microsoft Corporation
-
-Module Name:
-
-    solve_eqs2_tactic.h
-
-Abstract:
-
-    Tactic for solving variables
-
-Author:
-
-    Nikolaj Bjorner (nbjorner) 2022-10-30
-
---*/
-#pragma once
-
-#include "util/params.h"
-#include "tactic/tactic.h"
-#include "tactic/dependent_expr_state_tactic.h"
-#include "ast/simplifiers/solve_eqs.h"
-
-
-class solve_eqs2_tactic_factory : public dependent_expr_simplifier_factory {
-public:
-    dependent_expr_simplifier* mk(ast_manager& m, params_ref const& p, dependent_expr_state& s) override {
-        return alloc(euf::solve_eqs, m, s);
-    }
-};
-
-inline tactic * mk_solve_eqs2_tactic(ast_manager& m, params_ref const& p = params_ref()) {
-    return alloc(dependent_expr_state_tactic, m, p, alloc(solve_eqs2_tactic_factory), "solve-eqs");
-}
-
-#if 1
-inline tactic * mk_solve_eqs_tactic(ast_manager & m, params_ref const & p = params_ref()) {
-    return mk_solve_eqs2_tactic(m, p);
-}
-#endif
-
-
-/*
-  ADD_TACTIC("solve-eqs2", "solve for variables.", "mk_solve_eqs2_tactic(m, p)")
-*/
-
-

src/tactic/core/solve_eqs_tactic.h

@@ -1,37 +1,47 @@
 /*++
-Copyright (c) 2011 Microsoft Corporation
+Copyright (c) 2022 Microsoft Corporation
 
 Module Name:
 
-    solve_eqs_tactic.h
+    solve_eqs2_tactic.h
 
 Abstract:
 
-    Tactic for solving equations and performing gaussian elimination.
+    Tactic for solving variables
 
 Author:
 
-    Leonardo de Moura (leonardo) 2011-12-29.
-
-Revision History:
+    Nikolaj Bjorner (nbjorner) 2022-10-30
 
 --*/
 #pragma once
 
 #include "util/params.h"
-class ast_manager;
-class tactic;
+#include "tactic/tactic.h"
+#include "tactic/dependent_expr_state_tactic.h"
+#include "ast/simplifiers/solve_eqs.h"
 
-tactic * mk_solve_eqs1_tactic(ast_manager & m, params_ref const & p = params_ref());
 
-#if 0
+class solve_eqs2_tactic_factory : public dependent_expr_simplifier_factory {
+public:
+    dependent_expr_simplifier* mk(ast_manager& m, params_ref const& p, dependent_expr_state& s) override {
+        return alloc(euf::solve_eqs, m, s);
+    }
+};
+
+inline tactic * mk_solve_eqs2_tactic(ast_manager& m, params_ref const& p = params_ref()) {
+    return alloc(dependent_expr_state_tactic, m, p, alloc(solve_eqs2_tactic_factory), "solve-eqs");
+}
+
+#if 1
 inline tactic * mk_solve_eqs_tactic(ast_manager & m, params_ref const & p = params_ref()) {
-    return mk_solve_eqs1_tactic(m, p);
+    return mk_solve_eqs2_tactic(m, p);
 }
 #endif
 
+
 /*
-  ADD_TACTIC("solve-eqs", "eliminate variables by solving equations.", "mk_solve_eqs1_tactic(m, p)")
+  ADD_TACTIC("solve-eqs", "solve for variables.", "mk_solve_eqs2_tactic(m, p)")
 */
 
 

src/tactic/dependent_expr_state_tactic.h

@@ -81,6 +81,11 @@ public:
         m_simp->updt_params(m_params);
     }
 
+    void collect_param_descrs(param_descrs& r) override {
+        init();
+        m_simp->collect_param_descrs(r);
+    }
+
     tactic * translate(ast_manager & m) override {
         return alloc(dependent_expr_state_tactic, m, m_params, m_factory.get(), name());
     }

src/tactic/sls/sls_tactic.cpp

@@ -18,7 +18,6 @@ Notes:
 --*/
 #include "ast/normal_forms/nnf.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/bv/bv_size_reduction_tactic.h"
 #include "tactic/bv/max_bv_sharing_tactic.h"
 #include "tactic/core/simplify_tactic.h"

src/tactic/smtlogics/qfaufbv_tactic.cpp

@@ -17,7 +17,6 @@ Notes:
 
 --*/
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/simplify_tactic.h"
 #include "tactic/core/propagate_values_tactic.h"
 #include "tactic/bv/bit_blaster_tactic.h"

src/tactic/smtlogics/qfauflia_tactic.cpp

@@ -21,7 +21,6 @@ Notes:
 #include "tactic/core/propagate_values_tactic.h"
 #include "tactic/arith/propagate_ineqs_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/elim_uncnstr_tactic.h"
 #include "tactic/smtlogics/smt_tactic.h"
 

src/tactic/smtlogics/qfbv_tactic.cpp

@@ -20,7 +20,6 @@ Notes:
 #include "tactic/core/simplify_tactic.h"
 #include "tactic/core/propagate_values_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/elim_uncnstr_tactic.h"
 #include "tactic/bv/bit_blaster_tactic.h"
 #include "tactic/bv/bv1_blaster_tactic.h"

src/tactic/smtlogics/qfidl_tactic.cpp

@@ -21,7 +21,6 @@ Notes:
 #include "tactic/core/propagate_values_tactic.h"
 #include "tactic/arith/propagate_ineqs_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/elim_uncnstr_tactic.h"
 #include "tactic/arith/normalize_bounds_tactic.h"
 #include "tactic/arith/fix_dl_var_tactic.h"

src/tactic/smtlogics/qflia_tactic.cpp

@@ -22,7 +22,6 @@ Notes:
 #include "tactic/arith/propagate_ineqs_tactic.h"
 #include "tactic/arith/normalize_bounds_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/elim_uncnstr_tactic.h"
 #include "tactic/arith/add_bounds_tactic.h"
 #include "tactic/arith/pb2bv_tactic.h"

src/tactic/smtlogics/qfuf_tactic.cpp

@@ -21,7 +21,6 @@ Notes:
 #include "tactic/core/simplify_tactic.h"
 #include "tactic/core/symmetry_reduce_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/propagate_values_tactic.h"
 #include "tactic/smtlogics/smt_tactic.h"
 

src/tactic/smtlogics/qfufbv_tactic.cpp

@@ -21,7 +21,6 @@ Notes:
 #include "tactic/core/simplify_tactic.h"
 #include "tactic/core/propagate_values_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/elim_uncnstr_tactic.h"
 #include "tactic/bv/max_bv_sharing_tactic.h"
 #include "tactic/bv/bv_size_reduction_tactic.h"

src/tactic/smtlogics/quant_tactics.cpp

@@ -20,7 +20,6 @@ Revision History:
 #include "tactic/core/simplify_tactic.h"
 #include "tactic/core/propagate_values_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/elim_uncnstr_tactic.h"
 #include "qe/lite/qe_lite.h"
 #include "qe/qsat.h"

src/tactic/ufbv/ufbv_tactic.cpp

@@ -20,7 +20,6 @@ Notes:
 #include "tactic/core/simplify_tactic.h"
 #include "tactic/core/propagate_values_tactic.h"
 #include "tactic/core/solve_eqs_tactic.h"
-#include "tactic/core/solve_eqs2_tactic.h"
 #include "tactic/core/distribute_forall_tactic.h"
 #include "tactic/core/der_tactic.h"
 #include "tactic/core/reduce_args_tactic.h"