additional robustness check for incremental sat solver core when it recieves interpreted constants, added PB equality to interface and special handling of equalities to adddress performance gap documented in #755

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

contrib/cmake/src/solver/CMakeLists.txt

@@ -5,6 +5,7 @@ z3_add_component(solver
     mus.cpp
     solver.cpp
     solver_na2as.cpp
+    solver2tactic.cpp
     tactic2solver.cpp
   COMPONENT_DEPENDENCIES
     model

src/api/api_pb.cpp

@@ -57,5 +57,23 @@ extern "C" {
         Z3_CATCH_RETURN(0);
     }
 
+    Z3_ast Z3_API Z3_mk_pbeq(Z3_context c, unsigned num_args, 
+                             Z3_ast const args[], int _coeffs[],
+                             int k) {
+        Z3_TRY;
+        LOG_Z3_mk_pble(c, num_args, args, _coeffs, k);
+        RESET_ERROR_CODE();
+        pb_util util(mk_c(c)->m());
+        vector<rational> coeffs;
+        for (unsigned i = 0; i < num_args; ++i) {
+            coeffs.push_back(rational(_coeffs[i]));
+        }
+        ast* a = util.mk_eq(num_args, coeffs.c_ptr(), to_exprs(args), rational(k));
+        mk_c(c)->save_ast_trail(a);
+        check_sorts(c, a);
+        RETURN_Z3(of_ast(a));
+        Z3_CATCH_RETURN(0);
+    }
+
 
 };

src/api/dotnet/Context.cs

@@ -2640,6 +2640,21 @@ namespace Microsoft.Z3
                                                           AST.ArrayToNative(args),
                                                           coeffs, k));
         }
+
+        /// <summary>
+        /// Create a pseudo-Boolean equal constraint.
+        /// </summary>
+        public BoolExpr MkPBEq(int[] coeffs, BoolExpr[] args, int k)
+        {
+           Contract.Requires(args != null);
+           Contract.Requires(coeffs != null);
+           Contract.Requires(args.Length == coeffs.Length);
+           Contract.Requires(Contract.Result<BoolExpr[]>() != null);
+           CheckContextMatch<BoolExpr>(args);
+           return new BoolExpr(this, Native.Z3_mk_pbeq(nCtx, (uint) args.Length,
+                                                          AST.ArrayToNative(args),
+                                                          coeffs, k));
+        }
         #endregion
 
         #region Numerals

src/api/dotnet/Optimize.cs

@@ -258,11 +258,14 @@ namespace Microsoft.Z3
 	/// <summary>
 	/// Return a string the describes why the last to check returned unknown
 	/// </summary>	
-    	public String getReasonUnknown()
+    	public String ReasonUnknown
+    	{
+            get 
             {
                 Contract.Ensures(Contract.Result<string>() != null);
                 return Native.Z3_optimize_get_reason_unknown(Context.nCtx, NativeObject);
             }
+    	}
 
 
         /// <summary>

src/api/python/z3/z3.py

@@ -7654,6 +7654,26 @@ def PbLe(args, k):
         _coeffs[i] = coeffs[i]
     return BoolRef(Z3_mk_pble(ctx.ref(), sz, _args, _coeffs, k), ctx)
 
+def PbEq(args, k):
+    """Create a Pseudo-Boolean inequality k constraint.
+
+    >>> a, b, c = Bools('a b c')
+    >>> f = PbEq(((a,1),(b,3),(c,2)), 3)
+    """
+    args  = _get_args(args)
+    args, coeffs = zip(*args)
+    if __debug__:
+        _z3_assert(len(args) > 0, "Non empty list of arguments expected")
+    ctx   = _ctx_from_ast_arg_list(args)
+    if __debug__:
+        _z3_assert(ctx is not None, "At least one of the arguments must be a Z3 expression")
+    args = _coerce_expr_list(args, ctx)
+    _args, sz = _to_ast_array(args)
+    _coeffs = (ctypes.c_int * len(coeffs))()
+    for i in range(len(coeffs)):
+        _coeffs[i] = coeffs[i]
+    return BoolRef(Z3_mk_pbeq(ctx.ref(), sz, _args, _coeffs, k), ctx)
+
 
 def solve(*args, **keywords):
     """Solve the constraints `*args`.

src/api/z3_api.h

@@ -861,6 +861,9 @@ typedef enum
       - Z3_OP_PB_GE: Generalized Pseudo-Boolean cardinality constraint.
               Example  2*x + 3*y + 2*z >= 4
 
+      - Z3_OP_PB_EQ: Generalized Pseudo-Boolean equality constraint.
+              Example  2*x + 1*y + 2*z + 1*u = 4
+
       - Z3_OP_FPA_RM_NEAREST_TIES_TO_EVEN: Floating-point rounding mode RNE
 
       - Z3_OP_FPA_RM_NEAREST_TIES_TO_AWAY: Floating-point rounding mode RNA
@@ -1166,6 +1169,7 @@ typedef enum {
     Z3_OP_PB_AT_MOST=0x900,
     Z3_OP_PB_LE,
     Z3_OP_PB_GE,
+    Z3_OP_PB_EQ,
 
     // Floating-Point Arithmetic
     Z3_OP_FPA_RM_NEAREST_TIES_TO_EVEN,
@@ -3913,6 +3917,18 @@ extern "C" {
                              Z3_ast const args[], int coeffs[],
                              int k);
 
+    /**
+       \brief Pseudo-Boolean relations.
+
+       Encode k1*p1 + k2*p2 + ... + kn*pn = k
+
+       def_API('Z3_mk_pbeq', AST, (_in(CONTEXT), _in(UINT), _in_array(1,AST), _in_array(1,INT), _in(INT)))
+    */
+
+    Z3_ast Z3_API Z3_mk_pbeq(Z3_context c, unsigned num_args,
+                             Z3_ast const args[], int coeffs[],
+                             int k);
+
     /**
        \brief Convert a \c Z3_func_decl into \c Z3_ast. This is just type casting.
 

src/sat/sat_solver/inc_sat_solver.cpp

@@ -371,8 +371,18 @@ private:
             return l_undef;
         }
         g = m_subgoals[0];
+        expr_ref_vector atoms(m);
         TRACE("sat", g->display_with_dependencies(tout););
         m_goal2sat(*g, m_params, m_solver, m_map, dep2asm, true);
+        m_goal2sat.get_interpreted_atoms(atoms);
+        if (!atoms.empty()) {
+            std::stringstream strm;
+            strm << "interpreted atoms sent to SAT solver " << atoms;
+            TRACE("sat", std::cout << strm.str() << "\n";);
+            IF_VERBOSE(1, verbose_stream() << strm.str() << "\n";);
+            set_reason_unknown(strm.str().c_str());
+            return l_undef;
+        }
         return l_true;
     }
 

src/sat/tactic/goal2sat.cpp

@@ -59,6 +59,7 @@ struct goal2sat::imp {
     bool                        m_ite_extra;
     unsigned long long          m_max_memory;
     expr_ref_vector             m_trail;
+    expr_ref_vector             m_interpreted_atoms;
     bool                        m_default_external;
     
     imp(ast_manager & _m, params_ref const & p, sat::solver & s, atom2bool_var & map, dep2asm_map& dep2asm, bool default_external):
@@ -67,6 +68,7 @@ struct goal2sat::imp {
         m_map(map),
         m_dep2asm(dep2asm),
         m_trail(m),
+        m_interpreted_atoms(m),
         m_default_external(default_external) {
         updt_params(p);
         m_true = sat::null_bool_var;
@@ -128,6 +130,9 @@ struct goal2sat::imp {
                 m_map.insert(t, v);
                 l = sat::literal(v, sign);
                 TRACE("goal2sat", tout << "new_var: " << v << "\n" << mk_ismt2_pp(t, m) << "\n";);
+                if (ext && !is_uninterp_const(t)) {
+                    m_interpreted_atoms.push_back(t);
+                }
             }
         }
         else {
@@ -474,7 +479,7 @@ bool goal2sat::has_unsupported_bool(goal const & g) {
     return test<unsupported_bool_proc>(g);
 }
 
-goal2sat::goal2sat():m_imp(0) {
+goal2sat::goal2sat():m_imp(0), m_interpreted_atoms(0) {
 }
 
 void goal2sat::collect_param_descrs(param_descrs & r) {
@@ -492,10 +497,20 @@ struct goal2sat::scoped_set_imp {
     }
 };
 
+
 void goal2sat::operator()(goal const & g, params_ref const & p, sat::solver & t, atom2bool_var & m, dep2asm_map& dep2asm, bool default_external) {
     imp proc(g.m(), p, t, m, dep2asm, default_external);
     scoped_set_imp set(this, &proc);
     proc(g);
+    dealloc(m_interpreted_atoms);
+    m_interpreted_atoms = alloc(expr_ref_vector, g.m());
+    m_interpreted_atoms->append(proc.m_interpreted_atoms);
+}
+
+void goal2sat::get_interpreted_atoms(expr_ref_vector& atoms) {
+    if (m_interpreted_atoms) {
+        atoms.append(*m_interpreted_atoms);
+    }
 }
 
 

src/sat/tactic/goal2sat.h

@@ -38,8 +38,11 @@ class goal2sat {
     struct imp;
     imp *  m_imp;
     struct scoped_set_imp;
+    expr_ref_vector* m_interpreted_atoms;
+
 public:
     goal2sat();
+    ~goal2sat() { dealloc(m_interpreted_atoms); }
 
     typedef obj_map<expr, sat::literal> dep2asm_map;
 
@@ -59,6 +62,7 @@ public:
     */
     void operator()(goal const & g, params_ref const & p, sat::solver & t, atom2bool_var & m, dep2asm_map& dep2asm, bool default_external = false);
 
+    void get_interpreted_atoms(expr_ref_vector& atoms);
 
 };
 

src/smt/tactic/smt_tactic.cpp

@@ -24,63 +24,10 @@ Notes:
 #include"rewriter_types.h"
 #include"filter_model_converter.h"
 #include"ast_util.h"
+#include"solver2tactic.h"
 
 typedef obj_map<expr, expr *> expr2expr_map;
 
-void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clauses, ptr_vector<expr>& assumptions, expr2expr_map& bool2dep, ref<filter_model_converter>& fmc) {
-    expr2expr_map dep2bool;
-    ptr_vector<expr> deps;
-    ast_manager& m = g->m();
-    expr_ref_vector clause(m);
-    unsigned sz = g->size();
-    for (unsigned i = 0; i < sz; i++) {
-        expr * f            = g->form(i);
-        expr_dependency * d = g->dep(i);
-        if (d == 0 || !g->unsat_core_enabled()) {
-            clauses.push_back(f);
-        }
-        else {
-            // create clause (not d1 \/ ... \/ not dn \/ f) when the d's are the assumptions/dependencies of f.
-            clause.reset();
-            clause.push_back(f);
-            deps.reset();
-            m.linearize(d, deps);
-            SASSERT(!deps.empty()); // d != 0, then deps must not be empty
-            ptr_vector<expr>::iterator it  = deps.begin();
-            ptr_vector<expr>::iterator end = deps.end();
-            for (; it != end; ++it) {
-                expr * d = *it;
-                if (is_uninterp_const(d) && m.is_bool(d)) {
-                    // no need to create a fresh boolean variable for d
-                    if (!bool2dep.contains(d)) {
-                        assumptions.push_back(d);
-                        bool2dep.insert(d, d);
-                    }
-                    clause.push_back(m.mk_not(d));
-                }
-                else {
-                    // must normalize assumption
-                    expr * b = 0;
-                    if (!dep2bool.find(d, b)) {
-                        b = m.mk_fresh_const(0, m.mk_bool_sort());
-                        dep2bool.insert(d, b);
-                        bool2dep.insert(b, d);
-                        assumptions.push_back(b);
-                        if (!fmc) {
-                            fmc = alloc(filter_model_converter, m);
-                        }
-                        fmc->insert(to_app(b)->get_decl());
-                    }
-                    clause.push_back(m.mk_not(b));
-                }
-            }
-            SASSERT(clause.size() > 1);
-            expr_ref cls(m);
-            cls = mk_or(m, clause.size(), clause.c_ptr());
-            clauses.push_back(cls);
-        }
-    }
-}
 
 class smt_tactic : public tactic {
     smt_params                   m_params;

src/smt/tactic/smt_tactic.h

@@ -32,8 +32,6 @@ tactic * mk_smt_tactic(params_ref const & p = params_ref());
 tactic * mk_smt_tactic_using(bool auto_config = true, params_ref const & p = params_ref());
 
 
-void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clauses, ptr_vector<expr>& assumptions, obj_map<expr, expr*>& bool2dep, ref<filter_model_converter>& fmc);
-
 /*
   ADD_TACTIC("smt", "apply a SAT based SMT solver.", "mk_smt_tactic(p)") 
 */

src/solver/combined_solver.cpp

@@ -196,6 +196,7 @@ public:
 
     virtual lbool get_consequences(expr_ref_vector const& asms, expr_ref_vector const& vars, expr_ref_vector& consequences) {
         switch_inc_mode();
+        m_use_solver1_results = false;
         return m_solver2->get_consequences(asms, vars, consequences);
     }
 

src/solver/solver2tactic.cpp

@@ -0,0 +1,179 @@
+/*++
+Copyright (c) 2016 Microsoft Corporation
+
+Module Name:
+
+    solver2tactic.cpp
+
+Abstract:
+
+    Convert solver to a tactic.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2016-10-17
+
+Notes:
+   
+--*/
+
+#include "solver.h"
+#include "tactic.h"
+#include"filter_model_converter.h"
+#include "solver2tactic.h"
+#include "ast_util.h"
+
+typedef obj_map<expr, expr *> expr2expr_map;
+
+void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clauses, ptr_vector<expr>& assumptions, expr2expr_map& bool2dep, ref<filter_model_converter>& fmc) {
+    expr2expr_map dep2bool;
+    ptr_vector<expr> deps;
+    ast_manager& m = g->m();
+    expr_ref_vector clause(m);
+    unsigned sz = g->size();
+    for (unsigned i = 0; i < sz; i++) {
+        expr * f            = g->form(i);
+        expr_dependency * d = g->dep(i);
+        if (d == 0 || !g->unsat_core_enabled()) {
+            clauses.push_back(f);
+        }
+        else {
+            // create clause (not d1 \/ ... \/ not dn \/ f) when the d's are the assumptions/dependencies of f.
+            clause.reset();
+            clause.push_back(f);
+            deps.reset();
+            m.linearize(d, deps);
+            SASSERT(!deps.empty()); // d != 0, then deps must not be empty
+            ptr_vector<expr>::iterator it  = deps.begin();
+            ptr_vector<expr>::iterator end = deps.end();
+            for (; it != end; ++it) {
+                expr * d = *it;
+                if (is_uninterp_const(d) && m.is_bool(d)) {
+                    // no need to create a fresh boolean variable for d
+                    if (!bool2dep.contains(d)) {
+                        assumptions.push_back(d);
+                        bool2dep.insert(d, d);
+                    }
+                    clause.push_back(m.mk_not(d));
+                }
+                else {
+                    // must normalize assumption
+                    expr * b = 0;
+                    if (!dep2bool.find(d, b)) {
+                        b = m.mk_fresh_const(0, m.mk_bool_sort());
+                        dep2bool.insert(d, b);
+                        bool2dep.insert(b, d);
+                        assumptions.push_back(b);
+                        if (!fmc) {
+                            fmc = alloc(filter_model_converter, m);
+                        }
+                        fmc->insert(to_app(b)->get_decl());
+                    }
+                    clause.push_back(m.mk_not(b));
+                }
+            }
+            SASSERT(clause.size() > 1);
+            expr_ref cls(m);
+            cls = mk_or(m, clause.size(), clause.c_ptr());
+            clauses.push_back(cls);
+        }
+    }
+}
+
+class solver2tactic : public tactic {
+    ast_manager& m;
+    ref<solver> m_solver;
+    params_ref m_params;
+
+public:
+    solver2tactic(solver* s):
+        m(s->get_manager()),
+        m_solver(s)
+    {}
+    
+    virtual void updt_params(params_ref const & p) {
+        m_solver->updt_params(p);
+    }
+
+    virtual void collect_param_descrs(param_descrs & r) {
+        m_solver->collect_param_descrs(r);
+    }
+
+    virtual void operator()(/* in */  goal_ref const & in, 
+                            /* out */ goal_ref_buffer & result, 
+                            /* out */ model_converter_ref & mc, 
+                            /* out */ proof_converter_ref & pc,
+                            /* out */ expr_dependency_ref & core) {
+        expr_ref_vector clauses(m);
+        expr2expr_map               bool2dep;
+        ptr_vector<expr>            assumptions;
+        ref<filter_model_converter> fmc;
+        extract_clauses_and_dependencies(in, clauses, assumptions, bool2dep, fmc);
+        m_solver->push();
+        m_solver->assert_expr(clauses);
+        lbool r = m_solver->check_sat(assumptions.size(), assumptions.c_ptr()); 
+        switch (r) {
+        case l_true: 
+            if (in->models_enabled()) {
+                model_ref mdl;
+                m_solver->get_model(mdl);
+                mc = model2model_converter(mdl.get());
+                mc = concat(fmc.get(), mc.get());
+            }
+            in->reset();
+            result.push_back(in.get());
+            pc = 0;
+            core = 0;
+            break;
+        case l_false: {
+            in->reset();
+            proof* pr = 0;
+            expr_dependency* lcore = 0;
+            if (in->proofs_enabled()) {
+                pr = m_solver->get_proof();
+            }
+            if (in->unsat_core_enabled()) {
+                ptr_vector<expr> core;
+                m_solver->get_unsat_core(core);
+                for (unsigned i = 0; i < core.size(); ++i) {
+                    lcore = m.mk_join(lcore, m.mk_leaf(bool2dep.find(core[i])));
+                }
+            }
+            in->assert_expr(m.mk_false(), pr, lcore);
+            result.push_back(in.get());
+            mc = 0;
+            pc = 0;
+            core = 0;
+            break;
+        }
+        case l_undef:
+            if (m.canceled()) {
+                throw tactic_exception(Z3_CANCELED_MSG);
+            }
+            throw tactic_exception(m_solver->reason_unknown().c_str());
+        }
+        m_solver->pop(1);
+    }
+
+    virtual void collect_statistics(statistics & st) const {
+        m_solver->collect_statistics(st);
+    }
+    virtual void reset_statistics() {}
+
+    virtual void cleanup() {
+        m_solver = m_solver->translate(m, m_params);
+    }
+    virtual void reset() { cleanup(); }
+
+    virtual void set_logic(symbol const & l) {}
+
+    virtual void set_progress_callback(progress_callback * callback) {
+        m_solver->set_progress_callback(callback);
+    }
+
+    virtual tactic * translate(ast_manager & m) {
+        return alloc(solver2tactic, m_solver->translate(m, m_params));
+    }    
+};
+
+tactic* mk_solver2tactic(solver* s) { return alloc(solver2tactic, s); }

src/solver/solver2tactic.h

@@ -0,0 +1,30 @@
+/*++
+Copyright (c) 2016 Microsoft Corporation
+
+Module Name:
+
+    solver2tactic.h
+
+Abstract:
+
+    Convert solver to a tactic.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2016-10-17
+
+Notes:
+   
+--*/
+#ifndef SOLVER2TACTIC_H_
+#define SOLVER2TACTIC_H_
+
+#include "tactic.h"
+#include "filter_model_converter.h"
+class solver;
+
+tactic * mk_solver2tactic(solver* s);
+
+void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clauses, ptr_vector<expr>& assumptions, obj_map<expr, expr*>& bool2dep, ref<filter_model_converter>& fmc);
+
+#endif

src/solver/tactic2solver.cpp

@@ -160,6 +160,7 @@ lbool tactic2solver::check_sat_core(unsigned num_assumptions, expr * const * ass
         }
     }
     catch (z3_error & ex) {
+        TRACE("tactic2solver", tout << "exception: " << ex.msg() << "\n";);
         throw ex;
     }
     catch (z3_exception & ex) {

src/tactic/arith/bound_manager.cpp

@@ -79,12 +79,23 @@ static bool is_strict(decl_kind k) {
     return k == OP_LT || k == OP_GT;
 } 
 
+bool bound_manager::is_numeral(expr* v, numeral& n, bool& is_int) {
+    expr* w;
+    if (m_util.is_uminus(v, w) && is_numeral(w, n, is_int)) {
+        n.neg();
+        return true;
+    }
+    return m_util.is_numeral(v, n, is_int);
+}
+
 void bound_manager::operator()(expr * f, expr_dependency * d) {
     TRACE("bound_manager", tout << "processing:\n" << mk_ismt2_pp(f, m()) << "\n";);
     expr * v;
     numeral n;
     if (is_disjunctive_bound(f, d))
         return;
+    if (is_equality_bound(f, d))
+        return;
     bool pos = true;    
     while (m().is_not(f, f))
         pos = !pos;
@@ -99,10 +110,10 @@ void bound_manager::operator()(expr * f, expr_dependency * d) {
     expr * lhs = t->get_arg(0);
     expr * rhs = t->get_arg(1);
     bool is_int;
-    if (is_uninterp_const(lhs) && m_util.is_numeral(rhs, n, is_int)) {
+    if (is_uninterp_const(lhs) && is_numeral(rhs, n, is_int)) {
         v = lhs;
     }
-    else if (is_uninterp_const(rhs) && m_util.is_numeral(lhs, n, is_int)) {
+    else if (is_uninterp_const(rhs) && is_numeral(lhs, n, is_int)) {
         v = rhs;
         k = swap_decl(k);
     }
@@ -165,6 +176,26 @@ void bound_manager::insert_lower(expr * v, bool strict, numeral const & n, expr_
     }
 }
 
+bool bound_manager::is_equality_bound(expr * f, expr_dependency * d) {
+    expr* x, *y;
+    if (!m().is_eq(f, x, y)) {
+        return false;
+    }
+    if (!is_uninterp_const(x)) {
+        std::swap(x, y);
+    }
+    numeral n;
+    bool is_int;
+    if (is_uninterp_const(x) && is_numeral(y, n, is_int)) {
+        insert_lower(x, false, n, d);
+        insert_upper(x, false, n, d);
+        return true;
+    }
+    else {
+        return false;
+    }
+}
+
 bool bound_manager::is_disjunctive_bound(expr * f, expr_dependency * d) {
     numeral lo, hi, n;
     if (!m().is_or(f)) return false;
@@ -176,14 +207,14 @@ bool bound_manager::is_disjunctive_bound(expr * f, expr_dependency * d) {
         expr * e = to_app(f)->get_arg(i);
         if (!m().is_eq(e, x, y)) return false;
         if (is_uninterp_const(x) && 
-            m_util.is_numeral(y, n, is_int) && is_int && 
+            is_numeral(y, n, is_int) && is_int && 
             (x == v || v == 0)) {
             if (v == 0) { v = x; lo = hi = n; }
             if (n < lo) lo = n;
             if (n > hi) hi = n;
         }
         else if (is_uninterp_const(y) && 
-                 m_util.is_numeral(x, n, is_int) && is_int && 
+                 is_numeral(x, n, is_int) && is_int && 
                  (y == v || v == 0)) {
             if (v == 0) { v = y; lo = hi = n; }
             if (n < lo) lo = n;

src/tactic/arith/bound_manager.h

@@ -36,6 +36,8 @@ private:
     obj_map<expr, expr_dependency*> m_upper_deps;
     ptr_vector<expr>     m_bounded_vars;
     bool is_disjunctive_bound(expr * f, expr_dependency * d);
+    bool is_equality_bound(expr * f, expr_dependency * d);
+    bool is_numeral(expr* v, rational& n, bool& is_int);
     void insert_lower(expr * v, bool strict, numeral const & n, expr_dependency * d);
     void insert_upper(expr * v, bool strict, numeral const & n, expr_dependency * d);
 public:

src/tactic/nlsat_smt/nl_purify_tactic.cpp

@@ -59,6 +59,7 @@ Revision History:
 #include "model_smt2_pp.h"
 #include "expr_safe_replace.h"
 #include "ast_util.h"
+#include "solver2tactic.h"
 
 class nl_purify_tactic : public tactic {
 

src/tactic/portfolio/bounded_int2bv_solver.cpp

@@ -251,6 +251,16 @@ private:
                 }
                 sub.insert(e, t);
             }
+            else {
+                IF_VERBOSE(1, 
+                           verbose_stream() << "unprocessed entry: " << mk_pp(e, m) << "\n";
+                           if (bm.has_lower(e, lo, s1)) {
+                               verbose_stream() << "lower: " << lo << " " << s1 << "\n";
+                           } 
+                           if (bm.has_upper(e, hi, s2)) {
+                               verbose_stream() << "upper: " << hi << " " << s2 << "\n";
+                           });
+            }
         }
     }
 

src/tactic/portfolio/smt_strategic_solver.cpp

@@ -40,6 +40,7 @@ Notes:
 #include"inc_sat_solver.h"
 #include"fd_solver.h"
 #include"bv_rewriter.h"
+#include"solver2tactic.h"
 
 
 tactic * mk_tactic_for_logic(ast_manager & m, params_ref const & p, symbol const & logic) {
@@ -89,6 +90,8 @@ tactic * mk_tactic_for_logic(ast_manager & m, params_ref const & p, symbol const
         return mk_qffpbv_tactic(m, p);
     else if (logic=="HORN")
         return mk_horn_tactic(m, p);
+    else if (logic == "QF_FD")
+        return mk_solver2tactic(mk_fd_solver(m, p));
     //else if (logic=="QF_UFNRA")
     //    return mk_qfufnra_tactic(m, p);
     else 

src/util/sorting_network.h

@@ -202,7 +202,8 @@ Notes:
                 return ge(full, k, n, in.c_ptr());
             }
             else if (k == 1) {
-                return mk_at_most_1(full, n, xs);
+                literal_vector ors;
+                return mk_at_most_1(full, n, xs, ors);
             }
             else {
                 SASSERT(2*k <= n);
@@ -221,6 +222,9 @@ Notes:
             if (dualize(k, n, xs, in)) {
                 return eq(k, n, in.c_ptr());
             }
+            else if (k == 1) {
+                return mk_exactly_1(true, n, xs);
+            }
             else {
                 SASSERT(2*k <= n);
                 m_t = EQ;
@@ -238,12 +242,56 @@ Notes:
         
     private:
 
-        literal mk_at_most_1(bool full, unsigned n, literal const* xs) {
+
+        literal mk_and(literal l1, literal l2) {
+            literal result = fresh();
+            add_clause(ctx.mk_not(result), l1);
+            add_clause(ctx.mk_not(result), l2);
+            add_clause(ctx.mk_not(l1), ctx.mk_not(l2), result);
+            return result;
+        }
+
+        void mk_implies_or(literal l, unsigned n, literal const* xs) {
+            literal_vector lits(n, xs);
+            lits.push_back(ctx.mk_not(l));
+            add_clause(lits);
+        }
+
+        void mk_or_implies(literal l, unsigned n, literal const* xs) {
+            for (unsigned j = 0; j < n; ++j) {
+                add_clause(ctx.mk_not(xs[j]), l);
+            }
+        }
+
+        literal mk_or(literal_vector const& ors) {
+            if (ors.size() == 1) {
+                return ors[0];
+            }
+            literal result = fresh();
+            mk_implies_or(result, ors.size(), ors.c_ptr());
+            mk_or_implies(result, ors.size(), ors.c_ptr());
+            return result;
+        }
+
+        literal mk_exactly_1(bool full, unsigned n, literal const* xs) {
+            literal_vector ors;
+            literal r1 = mk_at_most_1(full, n, xs, ors);
+
+            if (full) {
+                r1 = mk_and(r1, mk_or(ors));
+            }
+            else {
+                mk_implies_or(r1, ors.size(), ors.c_ptr());
+            }
+            return r1;
+        }
+
+        literal mk_at_most_1(bool full, unsigned n, literal const* xs, literal_vector& ors) {
             TRACE("pb", tout << (full?"full":"partial") << " ";
                   for (unsigned i = 0; i < n; ++i) tout << xs[i] << " ";
                   tout << "\n";);
 
-            if (!full && n >= 4) {
+            if (false && !full && n >= 4) {
                 return mk_at_most_1_bimander(n, xs);
             }
             literal_vector in(n, xs);
@@ -252,9 +300,10 @@ Notes:
             literal_vector ands;
             ands.push_back(result);
             while (!in.empty()) {
-                literal_vector ors;
+                ors.reset();
                 unsigned i = 0;
                 unsigned n = in.size();
+                if (n + 1 == inc_size) ++inc_size;
                 bool last = n <= inc_size;
                 for (; i + inc_size < n; i += inc_size) {                    
                     mk_at_most_1_small(full, last, inc_size, in.c_ptr() + i, result, ands, ors);
@@ -267,7 +316,6 @@ Notes:
                 }
                 in.reset();
                 in.append(ors);
-                ors.reset();                
             }
             if (full) {
                 add_clause(ands);
@@ -278,23 +326,16 @@ Notes:
         void mk_at_most_1_small(bool full, bool last, unsigned n, literal const* xs, literal result, literal_vector& ands, literal_vector& ors) {
             SASSERT(n > 0);
             if (n == 1) {
-                if (!last) {
                 ors.push_back(xs[0]);                
-                }
                 return;
             }
-            if (!last) {
             literal ex = fresh();
-                for (unsigned j = 0; j < n; ++j) {
+            mk_or_implies(ex, n, xs);
-                    add_clause(ctx.mk_not(xs[j]), ex);
-                }
             if (full) {
-                    literal_vector lits(n, xs);
+                mk_implies_or(ex, n, xs);
-                    lits.push_back(ctx.mk_not(ex));
-                    add_clause(lits.size(), lits.c_ptr());
             }
             ors.push_back(ex);                
-            }
+            
             // result => xs[0] + ... + xs[n-1] <= 1
             for (unsigned i = 0; i < n; ++i) {
                 for (unsigned j = i + 1; j < n; ++j) {