fix #3557

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>
2025-04-13 12:28:44 +00:00 · 2020-04-03 16:37:59 -07:00 · 2020-04-03 16:37:59 -07:00 · 426e4cc75c
parent 0b856638e9
commit 426e4cc75c
65 changed files with 135 additions and 146 deletions
--- a/src/ackermannization/lackr.h
+++ b/src/ackermannization/lackr.h
@ -71,7 +71,7 @@ class lackr {
        //  timeout mechanism
        //
        void checkpoint() {
-            if (m.canceled()) {
+            if (!m.inc()) {
                throw tactic_exception(TACTIC_CANCELED_MSG);
            }
        }
--- a/src/api/api_opt.cpp
+++ b/src/api/api_opt.cpp
@ -162,11 +162,11 @@ extern "C" {
                r = to_optimize_ptr(o)->optimize(asms);
            }
            catch (z3_exception& ex) {
-                if (!mk_c(c)->m().canceled()) {
+                if (mk_c(c)->m().inc()) {
                    mk_c(c)->handle_exception(ex);
                }
                r = l_undef;
-                if (ex.msg() == std::string("canceled") && mk_c(c)->m().canceled()) {
+                if (ex.msg() == std::string("canceled") && !mk_c(c)->m().inc()) {
                    to_optimize_ptr(o)->set_reason_unknown(ex.msg());
                }
                else {
--- a/src/api/api_solver.cpp
+++ b/src/api/api_solver.cpp
@ -583,7 +583,7 @@ extern "C" {
            catch (z3_exception & ex) {
                to_solver_ref(s)->set_reason_unknown(eh);
                to_solver(s)->set_eh(nullptr);
-                if (!mk_c(c)->m().canceled()) {
+                if (mk_c(c)->m().inc()) {
                    mk_c(c)->handle_exception(ex);
                }
                return Z3_L_UNDEF;
--- a/src/ast/ast.h
+++ b/src/ast/ast.h
@ -1621,7 +1621,8 @@ public:
    }

    reslimit& limit() { return m_limit; }
-    bool canceled() { return !limit().inc(); }
+    // bool canceled() { return !limit().inc(); }
+    bool inc() { return limit().inc(); }

    void register_plugin(symbol const & s, decl_plugin * plugin);

--- a/src/ast/normal_forms/nnf.cpp
+++ b/src/ast/normal_forms/nnf.cpp
@ -382,7 +382,7 @@ struct nnf::imp {
    void checkpoint() {
        if (memory::get_allocation_size() > m_max_memory)
            throw nnf_exception(Z3_MAX_MEMORY_MSG);
-        if (m.canceled()) 
+        if (!m.inc()) 
            throw nnf_exception(m.limit().get_cancel_msg());
    }

--- a/src/ast/rewriter/bit_blaster/bit_blaster_tpl_def.h
+++ b/src/ast/rewriter/bit_blaster/bit_blaster_tpl_def.h
@ -27,7 +27,7 @@ template<typename Cfg>
 void bit_blaster_tpl<Cfg>::checkpoint() {
    if (memory::get_allocation_size() > m_max_memory)
        throw rewriter_exception(Z3_MAX_MEMORY_MSG);
-    if (m().canceled())
+    if (!m().inc())
        throw rewriter_exception(m().limit().get_cancel_msg());
 }

--- a/src/ast/rewriter/rewriter_def.h
+++ b/src/ast/rewriter/rewriter_def.h
@ -699,7 +699,7 @@ template<typename Config>
 template<bool ProofGen>
 void rewriter_tpl<Config>::main_loop(expr * t, expr_ref & result, proof_ref & result_pr) {
    result_pr = nullptr;
-    if (m().canceled()) {
+    if (!m().inc()) {
        if (m_cancel_check) {
            reset();
            throw rewriter_exception(m().limit().get_cancel_msg());
@ -738,7 +738,7 @@ template<bool ProofGen>
 void rewriter_tpl<Config>::resume_core(expr_ref & result, proof_ref & result_pr) {
    SASSERT(!frame_stack().empty());
    while (!frame_stack().empty()) {
-        if (m().canceled()) {
+        if (!m().inc()) {
            if (m_cancel_check) {
                reset();
                throw rewriter_exception(m().limit().get_cancel_msg());
--- a/src/cmd_context/cmd_context.cpp
+++ b/src/cmd_context/cmd_context.cpp
@ -1579,7 +1579,7 @@ void cmd_context::check_sat(unsigned num_assumptions, expr * const * assumptions
        scoped_rlimit _rlimit(m().limit(), rlimit);
        try {
            r = m_solver->check_sat(num_assumptions, assumptions);
-            if (r == l_undef && m().canceled()) {
+            if (r == l_undef && !m().inc()) {
                m_solver->set_reason_unknown(eh);
            }
        }
@ -1587,7 +1587,7 @@ void cmd_context::check_sat(unsigned num_assumptions, expr * const * assumptions
            throw ex;
        }
        catch (z3_exception & ex) {
-            if (m().canceled()) {
+            if (!m().inc()) {
                m_solver->set_reason_unknown(eh);
            }
            else {
--- a/src/math/grobner/grobner.cpp
+++ b/src/math/grobner/grobner.cpp
@ -656,7 +656,7 @@ grobner::equation * grobner::simplify(equation const * source, equation * target
            simplify(target);
        }
    }
-    while (simplified && !m_manager.canceled());
+    while (simplified && m_manager.inc());
    TRACE("grobner", tout << "result: "; display_equation(tout, *target););
    return result ? target : nullptr;
 }
@ -680,7 +680,7 @@ grobner::equation * grobner::simplify_using_processed(equation * eq) {
                simplified = true;
                eq         = new_eq;
            }
-            if (m_manager.canceled()) {
+            if (!m_manager.inc()) {
                return nullptr;
            }
        }        
@ -736,7 +736,7 @@ bool grobner::simplify_processed(equation * eq) {
    ptr_buffer<equation> to_delete;
    equation_set::iterator it  = m_processed.begin();
    equation_set::iterator end = m_processed.end();
-    for (; it != end && !m_manager.canceled(); ++it) {
+    for (; it != end && m_manager.inc(); ++it) {
        equation * curr        = *it;
        m_changed_leading_term = false;
        // if the leading term is simplified, then the equation has to be moved to m_to_process
@ -770,7 +770,7 @@ bool grobner::simplify_processed(equation * eq) {
        m_processed.erase(eq);
    for (equation* eq : to_delete) 
        del_equation(eq);
-    return !m_manager.canceled();
+    return m_manager.inc();
 }

 /**
@ -908,7 +908,7 @@ bool grobner::compute_basis_step() {
        m_equations_to_unfreeze.push_back(eq);
        eq = new_eq;
    }
-    if (m_manager.canceled()) return false;
+    if (!m_manager.inc()) return false;
    if (!simplify_processed(eq)) return false;
    superpose(eq);
    m_processed.insert(eq);
@ -919,7 +919,7 @@ bool grobner::compute_basis_step() {

 bool grobner::compute_basis(unsigned threshold) {
    compute_basis_init();
-    while (m_num_new_equations < threshold && !m_manager.canceled()) {
+    while (m_num_new_equations < threshold && m_manager.inc()) {
        if (compute_basis_step()) return true;
    }
    return false;
--- a/src/math/subpaving/tactic/expr2subpaving.cpp
+++ b/src/math/subpaving/tactic/expr2subpaving.cpp
@ -93,7 +93,7 @@ struct expr2subpaving::imp {
    }

    void checkpoint() {
-        if (m().canceled())
+        if (!m().inc())
            throw default_exception(Z3_CANCELED_MSG);
    }

--- a/src/muz/base/dl_context.h
+++ b/src/muz/base/dl_context.h
@ -497,7 +497,7 @@ namespace datalog {
        // -----------------------------------

        bool canceled() {
-            return m.canceled() && (m_last_status = CANCELED, true);
+            return !m.inc() && (m_last_status = CANCELED, true);
        }

        void cleanup();
--- a/src/muz/base/hnf.cpp
+++ b/src/muz/base/hnf.cpp
@ -172,7 +172,7 @@ public:
    }

    bool checkpoint() {
-        return !m.canceled();
+        return m.inc();
    }

    void set_name(symbol const& n) {
--- a/src/muz/bmc/dl_bmc_engine.cpp
+++ b/src/muz/bmc/dl_bmc_engine.cpp
@ -26,6 +26,7 @@ Revision History:
 #include "ast/scoped_proof.h"
 #include "smt/smt_solver.h"
 #include "tactic/fd_solver/fd_solver.h"
+#include "tactic/tactic.h"
 #include "muz/base/dl_context.h"
 #include "muz/base/dl_rule_transformer.h"
 #include "muz/bmc/dl_bmc_engine.h"
@ -35,6 +36,7 @@ Revision History:
 #include "muz/transforms/dl_mk_rule_inliner.h"
 #include "muz/base/fp_params.hpp"

+
 namespace datalog {

    // ---------------------------------------------------------------------------
@ -485,7 +487,7 @@ namespace datalog {
        }

        proof_ref get_proof(model_ref& md, func_decl* pred, app* prop, unsigned level) {
-            if (m.canceled()) {
+            if (!m.inc()) {
                return proof_ref(nullptr, m);
            }
            TRACE("bmc", tout << "Predicate: " << pred->get_name() << "\n";);
@ -1173,7 +1175,7 @@ namespace datalog {
    private:

        void get_model(unsigned level) {
-            if (m.canceled()) {
+            if (!m.inc()) {
                return;
            }
            rule_manager& rm = b.m_ctx.get_rule_manager();
@ -1520,9 +1522,7 @@ namespace datalog {
    }

    void bmc::checkpoint() {
-        if (m.canceled()) {
-            throw default_exception(Z3_CANCELED_MSG);
-        }
+        tactic::checkpoint(m);
    }

    void bmc::display_certificate(std::ostream& out) const {
--- a/src/muz/spacer/spacer_context.cpp
+++ b/src/muz/spacer/spacer_context.cpp
@ -2759,11 +2759,8 @@ lbool context::solve(unsigned from_lvl)
 }


-void context::checkpoint()
-{
-    if (m.canceled ()) {
-        throw default_exception("spacer canceled");
-    }
+void context::checkpoint() {
+    tactic::checkpoint(m);
 }

 unsigned context::get_cex_depth()
--- a/src/muz/tab/tab_context.cpp
+++ b/src/muz/tab/tab_context.cpp
@ -581,7 +581,7 @@ namespace tb {

        // extract pre_cond => post_cond validation obligation from match.
        bool find_match(unsigned& subsumer) {
-            for (unsigned i = 0; !m.canceled() && i < m_index.size(); ++i) {
+            for (unsigned i = 0; m.inc() && i < m_index.size(); ++i) {
                if (match_rule(i)) {
                    subsumer = m_index[i]->get_seqno();
                    return true;
@ -618,7 +618,7 @@ namespace tb {

            app* q = g.get_predicate(predicate_index);

-            for (unsigned i = 0; !m.canceled() && i < m_preds.size(); ++i) {
+            for (unsigned i = 0; m.inc() && i < m_preds.size(); ++i) {
                app* p = m_preds[i].get();
                m_subst.push_scope();
                unsigned limit = m_sideconds.size();
@ -647,7 +647,7 @@ namespace tb {
            expr_ref_vector fmls(m_sideconds);
            m_subst.reset_cache();

-            for (unsigned i = 0; !m.canceled() && i < fmls.size(); ++i) {
+            for (unsigned i = 0; m.inc() && i < fmls.size(); ++i) {
                m_subst.apply(2, deltas, expr_offset(fmls[i].get(), 0), q);
                fmls[i] = q;
            }
@ -664,7 +664,7 @@ namespace tb {
                }
            }
            m_rw.mk_and(fmls.size(), fmls.c_ptr(), postcond);
-            if (m.canceled()) {
+            if (!m.inc()) {
                return false;
            }
            if (m.is_false(postcond)) {
@ -1493,7 +1493,7 @@ namespace datalog {
            m_status      = l_undef;
            while (true) {
                IF_VERBOSE(2, verbose_stream() << m_instruction << "\n";);
-                if (m.canceled()) {
+                if (!m.inc()) {
                    cleanup();
                    return l_undef;
                }
--- a/src/muz/transforms/dl_mk_karr_invariants.cpp
+++ b/src/muz/transforms/dl_mk_karr_invariants.cpp
@ -214,7 +214,7 @@ namespace datalog {

        get_invariants(*src_loop);

-        if (m.canceled()) {
+        if (!m.inc()) {
            return nullptr;
        }

--- a/src/opt/maxlex.cpp
+++ b/src/opt/maxlex.cpp
@ -159,7 +159,7 @@ namespace opt {
                switch (is_sat) {
                case l_true:
                    update_assignment();
-                    SASSERT(soft.value == l_true || m.canceled());
+                    SASSERT(soft.value == l_true || m.limit().get_cancel_flag());
                    break;
                case l_false:
                    soft.set_value(l_false);
--- a/src/opt/maxres.cpp
+++ b/src/opt/maxres.cpp
@ -207,7 +207,7 @@ public:
                  s().display(tout << m_asms << "\n") << "\n";
                  display(tout););
            is_sat = check_sat_hill_climb(m_asms);
-            if (m.canceled()) {
+            if (!m.inc()) {
                return l_undef;
            }
            switch (is_sat) {
@ -247,7 +247,7 @@ public:
        if (is_sat != l_true) return is_sat;
        while (m_lower < m_upper) {
            is_sat = check_sat_hill_climb(m_asms);
-            if (m.canceled()) {
+            if (!m.inc()) {
                return l_undef;
            }
            switch (is_sat) {
@ -862,7 +862,7 @@ public:
               tout << "other solver\n";
               s().display(tout);
               );
-        VERIFY(is_sat == l_false || m.canceled());
+        VERIFY(is_sat == l_false || !m.inc());
    }

    void verify_assumptions() {
--- a/src/opt/opt_context.cpp
+++ b/src/opt/opt_context.cpp
@ -615,7 +615,7 @@ namespace opt {


    std::string context::reason_unknown() const { 
-        if (m.canceled()) {
+        if (!m.inc()) {
            return Z3_CANCELED_MSG;
        }
        if (m_solver.get()) {
--- a/src/opt/opt_pareto.cpp
+++ b/src/opt/opt_pareto.cpp
@ -36,7 +36,7 @@ namespace opt {
                m_solver->get_model(m_model);
                solver::scoped_push _s(*m_solver.get());
                while (is_sat == l_true) {
-                    if (m.canceled()) {
+                    if (!m.inc()) {
                        return l_undef;
                    }
                    
@ -96,7 +96,7 @@ namespace opt {
    lbool oia_pareto::operator()() {
        solver::scoped_push _s(*m_solver.get());
        lbool is_sat = m_solver->check_sat(0, nullptr);
-        if (m.canceled()) {
+        if (!m.inc()) {
            is_sat = l_undef;
        }
        if (is_sat == l_true) {
--- a/src/opt/optsmt.cpp
+++ b/src/opt/optsmt.cpp
@ -71,7 +71,7 @@ namespace opt {
        expr* vars[1];

        solver::scoped_push _push(*m_s);
-        while (is_sat == l_true && !m.canceled()) {
+        while (is_sat == l_true && m.inc()) {

            tmp = m.mk_fresh_const("b", m.mk_bool_sort());            
            vars[0] = tmp;
@ -83,7 +83,7 @@ namespace opt {
            }
        }      
        
-        if (m.canceled() || is_sat == l_undef) {
+        if (!m.inc() || is_sat == l_undef) {
            return l_undef;
        }

@ -110,7 +110,7 @@ namespace opt {
        unsigned num_scopes = 0;
        unsigned delta_index = 0;    // index of objective to speed up.

-        while (!m.canceled()) {
+        while (m.inc()) {
            SASSERT(delta_per_step.is_int());
            SASSERT(delta_per_step.is_pos());
            is_sat = m_s->check_sat(0, nullptr);
@ -176,7 +176,7 @@ namespace opt {
            }
        }
        
-        if (m.canceled() || is_sat == l_undef) {
+        if (!m.inc() || is_sat == l_undef) {
            return l_undef;
        }
        
@ -208,7 +208,7 @@ namespace opt {
        rational delta_per_step(1);
        unsigned num_scopes = 0;

-        while (!m.canceled()) {
+        while (m.inc()) {
            SASSERT(delta_per_step.is_int());
            SASSERT(delta_per_step.is_pos());
            is_sat = m_s->check_sat(0, nullptr);
@ -265,7 +265,7 @@ namespace opt {
            return l_false;
        }
        
-        if (m.canceled() || is_sat == l_undef) {
+        if (!m.inc() || is_sat == l_undef) {
            return l_undef;
        }

@ -315,7 +315,7 @@ namespace opt {
            lbool is_sat = l_true;

            solver::scoped_push _push(*m_s);
-            while (!m.canceled()) {
+            while (m.inc()) {
                m_s->assert_expr(fml);
                TRACE("opt", tout << fml << "\n";);
                is_sat = m_s->check_sat(1,vars);
@ -349,7 +349,7 @@ namespace opt {
        bound = mk_or(m_lower_fmls);
        m_s->assert_expr(bound);
        
-        if (m.canceled()) {
+        if (!m.inc()) {
            return l_undef;
        }
        return geometric_opt();
@ -418,7 +418,7 @@ namespace opt {

        vector<inf_eps> mid;

-        for (unsigned i = 0; i < m_lower.size() && !m.canceled(); ++i) {
+        for (unsigned i = 0; i < m_lower.size() && m.inc(); ++i) {
            if (m_lower[i] < m_upper[i]) {
                mid.push_back((m_upper[i]+m_lower[i])/rational(2));
                bound = m_s->mk_ge(i, mid[i]);
@ -430,7 +430,7 @@ namespace opt {
            }
        }
        bool progress = false;
-        for (unsigned i = 0; i < m_lower.size() && !m.canceled(); ++i) {
+        for (unsigned i = 0; i < m_lower.size() && m.inc(); ++i) {
            if (m_lower[i] <= mid[i] && mid[i] <= m_upper[i] && m_lower[i] < m_upper[i]) {
                th.enable_record_conflict(bounds[i].get());
                lbool is_sat = m_s->check_sat(1, bounds.c_ptr() + i);
@ -460,7 +460,7 @@ namespace opt {
                progress = true;
            }
        }
-        if (m.canceled()) {
+        if (!m.inc()) {
            return l_undef;
        }
        if (!progress) {
--- a/src/opt/pb_sls.cpp
+++ b/src/opt/pb_sls.cpp
@ -194,7 +194,7 @@ namespace smt {
                while (m_max_flips > 0) {
                    --m_max_flips;
                    literal lit = flip();
-                    if (m.canceled()) {
+                    if (!m.inc()) {
                        return l_undef;
                    }
                    IF_VERBOSE(3, verbose_stream() 
--- a/src/opt/sortmax.cpp
+++ b/src/opt/sortmax.cpp
@ -90,7 +90,7 @@ namespace opt {
                s().assert_expr(out[first]);
                is_sat = s().check_sat(0, nullptr);
                TRACE("opt", tout << is_sat << "\n"; s().display(tout); tout << "\n";);
-                if (m.canceled()) {
+                if (!m.inc()) {
                    is_sat = l_undef;
                }
                if (is_sat == l_true) {
--- a/src/opt/wmax.cpp
+++ b/src/opt/wmax.cpp
@ -77,9 +77,9 @@ namespace opt {
            TRACE("opt", 
                  s().display(tout)<< "\n";
                  tout << "lower: " << m_lower << " upper: " << m_upper << "\n";);
-            while (!m.canceled() && m_lower < m_upper) {
+            while (m.inc() && m_lower < m_upper) {
                is_sat = s().check_sat(0, nullptr);
-                if (m.canceled()) {
+                if (!m.inc()) {
                    is_sat = l_undef;
                }
                if (is_sat == l_undef) {
@ -106,7 +106,7 @@ namespace opt {

            update_assignment();
            
-            if (!m.canceled() && is_sat == l_undef && m_lower == m_upper) {
+            if (m.inc() && is_sat == l_undef && m_lower == m_upper) {
                is_sat = l_true;
            }
            if (is_sat == l_false) {
--- a/src/qe/qe.cpp
+++ b/src/qe/qe.cpp
@ -2049,7 +2049,7 @@ namespace qe {
        }
                
        void checkpoint() {
-            if (m.canceled()) 
+            if (!m.inc()) 
                throw tactic_exception(m.limit().get_cancel_msg());
        }

--- a/src/qe/qe_arith.cpp
+++ b/src/qe/qe_arith.cpp
@ -65,9 +65,9 @@ namespace qe {
            DEBUG_CODE(expr_ref val(m); 
                       eval(lit, val); 
                       CTRACE("qe", !m.is_true(val), tout << mk_pp(lit, m) << " := " << val << "\n";);
-                       SASSERT(m.canceled() || m.is_true(val)););
+                       SASSERT(m.limit().get_cancel_flag() || m.is_true(val)););

-            if (!m.limit().inc()) 
+            if (!m.inc()) 
                return false;
            
            TRACE("opt", tout << mk_pp(lit, m) << " " << a.is_lt(lit) << " " << a.is_gt(lit) << "\n";);
--- a/src/qe/qe_lite.cpp
+++ b/src/qe/qe_lite.cpp
@ -682,8 +682,7 @@ namespace qel {
        }

        void checkpoint() {
-            if (m.canceled())
-                throw tactic_exception(m.limit().get_cancel_msg());
+            tactic::checkpoint(m);
        }

    public:
@ -870,8 +869,7 @@ namespace qel {
        }

        void checkpoint() {
-            if (m.canceled())
-                throw tactic_exception(m.limit().get_cancel_msg());
+            tactic::checkpoint(m);
    }

    public:
@ -2144,8 +2142,7 @@ namespace fm {
        }

        void checkpoint() {
-            if (m.canceled())
-                throw tactic_exception(m.limit().get_cancel_msg());
+            tactic::checkpoint(m);
        }
    public:

@ -2411,8 +2408,7 @@ class qe_lite_tactic : public tactic {
    qe_lite                  m_qe;

    void checkpoint() {
-        if (m.canceled())
-            throw tactic_exception(m.limit().get_cancel_msg());
+        tactic::checkpoint(m);
    }

 #if 0
--- a/src/qe/qe_mbp.cpp
+++ b/src/qe/qe_mbp.cpp
@ -207,10 +207,10 @@ class mbp::impl {
                continue;
            }
            m_visited.mark(e);
-            if (m.is_bool(e) && !m.is_true(e) && !m.is_false(e) && !m.canceled()) {
+            if (m.is_bool(e) && !m.is_true(e) && !m.is_false(e) && m.inc()) {
                expr_ref val = eval(e);
                TRACE("qe", tout << "found: " << mk_pp(e, m) << "\n";);
-                if (m.canceled())
+                if (!m.inc())
                    continue;
                SASSERT(m.is_true(val) || m.is_false(val));
                if (!m_bool_visited.is_marked(e)) {
--- a/src/qe/qe_tactic.cpp
+++ b/src/qe/qe_tactic.cpp
@ -43,8 +43,7 @@ class qe_tactic : public tactic {
        }

        void checkpoint() {
-            if (m.canceled()) 
-                throw tactic_exception(m.limit().get_cancel_msg());
+            tactic::checkpoint(m);
        }

        void operator()(goal_ref const & g, 
--- a/src/qe/qsat.cpp
+++ b/src/qe/qsat.cpp
@ -856,9 +856,7 @@ namespace qe {
        }
        
        void check_cancel() {
-            if (m.canceled()) {
-                throw tactic_exception(m.limit().get_cancel_msg());
-            }
+            tactic::checkpoint(m);
        }
        
        void display(std::ostream& out) const {
@ -1125,7 +1123,7 @@ namespace qe {
            expr_ref_vector fmls(m);
            fmls.append(core.size(), core.c_ptr());
            s.get_assertions(fmls);
-            return check_fmls(fmls) || m.canceled();
+            return check_fmls(fmls) || !m.inc();
 #endif
        }

@ -1138,7 +1136,7 @@ namespace qe {
            lbool is_sat = solver.check();
            CTRACE("qe", is_sat != l_false, 
                   tout << fmls << "\nare not unsat\n";);
-            return (is_sat == l_false) || m.canceled();
+            return (is_sat == l_false) || !m.inc();
        }

        bool validate_model(expr_ref_vector const& asms) {
@ -1157,7 +1155,7 @@ namespace qe {
        bool validate_model(model& mdl, unsigned sz, expr* const* fmls) {
            expr_ref val(m);
            for (unsigned i = 0; i < sz; ++i) {
-                if (!m_model->is_true(fmls[i]) && !m.canceled()) {
+                if (!m_model->is_true(fmls[i]) && m.inc()) {
                    TRACE("qe", tout << "Formula does not evaluate to true in model: " << mk_pp(fmls[i], m) << "\n";);
                    return false;
                } 
@ -1189,7 +1187,7 @@ namespace qe {
                TRACE("qe", tout << "Projection is false in model\n";);
                return false;
            }
-            if (m.canceled()) {
+            if (!m.inc()) {
                return true;
            }
            for (unsigned i = 0; i < m_avars.size(); ++i) {
--- a/src/sat/tactic/goal2sat.cpp
+++ b/src/sat/tactic/goal2sat.cpp
@ -779,7 +779,7 @@ struct goal2sat::imp {
        }
        while (!m_frame_stack.empty()) {
        loop:
-            if (m.canceled())
+            if (!m.inc())
                throw tactic_exception(m.limit().get_cancel_msg());
            if (memory::get_allocation_size() > m_max_memory)
                throw tactic_exception(TACTIC_MAX_MEMORY_MSG);
@ -1098,7 +1098,7 @@ struct sat2goal::imp {
    }

    void checkpoint() {
-        if (m.canceled())
+        if (!m.inc())
            throw tactic_exception(m.limit().get_cancel_msg());
        if (memory::get_allocation_size() > m_max_memory)
            throw tactic_exception(TACTIC_MAX_MEMORY_MSG);
--- a/src/smt/asserted_formulas.cpp
+++ b/src/smt/asserted_formulas.cpp
@ -180,13 +180,13 @@ void asserted_formulas::get_assertions(ptr_vector<expr> & result) const {
 void asserted_formulas::push_scope() {
    reduce();
    commit();
-    SASSERT(inconsistent() || m_qhead == m_formulas.size() || m.canceled());
+    SASSERT(inconsistent() || m_qhead == m_formulas.size() || m.limit().get_cancel_flag());
    TRACE("asserted_formulas_scopes", tout << "before push: " << m_scopes.size() << "\n";);
    m_scoped_substitution.push();
    m_scopes.push_back(scope());
    scope & s = m_scopes.back();
    s.m_formulas_lim = m_formulas.size();
-    SASSERT(inconsistent() || s.m_formulas_lim == m_qhead || m.canceled());
+    SASSERT(inconsistent() || s.m_formulas_lim == m_qhead || m.limit().get_cancel_flag());
    s.m_inconsistent_old = m_inconsistent;
    m_defined_names.push();
    m_elim_term_ite.push();
--- a/src/smt/asserted_formulas.h
+++ b/src/smt/asserted_formulas.h
@ -212,7 +212,7 @@ class asserted_formulas {
    bool invoke(simplify_fmls& s);
    void swap_asserted_formulas(vector<justified_expr>& new_fmls);
    void push_assertion(expr * e, proof * pr, vector<justified_expr>& result);
-    bool canceled() { return m.canceled(); }
+    bool canceled() { return !m.inc(); }
    bool check_well_sorted() const;
    unsigned get_total_size() const;

--- a/src/smt/smt_consequences.cpp
+++ b/src/smt/smt_consequences.cpp
@ -522,7 +522,7 @@ namespace smt {
        unsigned num_restarts = 0;

        while (true) {
-            if (m.canceled()) {
+            if (!m.inc()) {
                is_sat = l_undef;
                break;
            }
--- a/src/smt/smt_context_inv.cpp
+++ b/src/smt/smt_context_inv.cpp
@ -264,7 +264,7 @@ namespace smt {
    bool context::check_th_diseq_propagation() const {
        TRACE("check_th_diseq_propagation", tout << "m_propagated_th_diseqs.size() " << m_propagated_th_diseqs.size() << "\n";);
        int num = get_num_bool_vars();
-        if (inconsistent() || get_manager().canceled()) { 
+        if (inconsistent() || get_manager().limit().get_cancel_flag()) { 
            return true;
        }
        for (bool_var v = 0; v < num; v++) {
--- a/src/smt/tactic/ctx_solver_simplify_tactic.cpp
+++ b/src/smt/tactic/ctx_solver_simplify_tactic.cpp
@ -96,7 +96,7 @@ protected:
        m_solver.push();
        reduce(fml);
        m_solver.pop(1);
-        if (m.canceled())
+        if (!m.inc())
            return;
        SASSERT(m_solver.get_scope_level() == 0);
        TRACE("ctx_solver_simplify_tactic",
@ -172,7 +172,7 @@ protected:
        names.push_back(n);
        m_solver.push();

-        while (!todo.empty() && !m.canceled()) {            
+        while (!todo.empty() && m.inc()) {            
            expr_ref res(m);
            args.reset();
            expr* e    = todo.back().m_expr;
@ -244,7 +244,7 @@ protected:
            names.pop_back();
            m_solver.pop(1);
        }
-        if (!m.canceled()) {
+        if (m.inc()) {
            VERIFY(cache.find(fml, path_r));
            result = path_r.m_expr;
        }
--- a/src/smt/tactic/unit_subsumption_tactic.cpp
+++ b/src/smt/tactic/unit_subsumption_tactic.cpp
@ -57,9 +57,7 @@ struct unit_subsumption_tactic : public tactic {
    }
    
    void checkpoint() {
-        if (m.canceled()) {
-            throw tactic_exception(m.limit().get_cancel_msg());
-        }
+        tactic::checkpoint(m);
    }

    void reduce_core(goal_ref const& g, goal_ref_buffer& result) {
--- a/src/smt/theory_arith_inv.h
+++ b/src/smt/theory_arith_inv.h
@ -215,7 +215,7 @@ namespace smt {

    template<typename Ext>
    bool theory_arith<Ext>::valid_assignment() const {
-        if (get_manager().canceled())
+        if (get_manager().limit().get_cancel_flag())
            return true;
        if (valid_row_assignment() &&
            satisfy_bounds() &&
--- a/src/smt/theory_bv.cpp
+++ b/src/smt/theory_bv.cpp
@ -1862,7 +1862,10 @@ namespace smt {
                    literal l = lits[i];
                    if (l.var() == true_bool_var) {
                        unsigned is_true = (l == true_literal);
-                        SASSERT(!bits[!is_true][i]); // no complementary bits
+                        if (bits[!is_true][i]) {
+                            // expect a conflict later on.
+                            return true;
+                        }
                        if (!bits[is_true][i]) {
                            bits[is_true][i] = true;
                            num_bits++;
@ -1888,6 +1891,8 @@ namespace smt {
    }

    bool theory_bv::check_invariant() {
+        if (get_manager().limit().get_cancel_flag())
+            return true;
        if (get_context().inconsistent())
            return true;
        unsigned num = get_num_vars();
--- a/src/smt/theory_lra.cpp
+++ b/src/smt/theory_lra.cpp
@ -164,7 +164,7 @@ class theory_lra::imp {
        imp& m_imp;
    public:
        resource_limit(imp& i): m_imp(i) { }
-        bool get_cancel_flag() override { return m_imp.m.canceled(); }
+        bool get_cancel_flag() override { return !m_imp.m.inc(); }
    };


@ -1563,7 +1563,7 @@ public:

    void init_variable_values() {
        reset_variable_values();
-        if (!m.canceled() && m_solver.get() && th.get_num_vars() > 0) {            
+        if (m.inc() && m_solver.get() && th.get_num_vars() > 0) {            
            TRACE("arith", display(tout << "update variable values\n"););
            lp().get_model(m_variable_values);
        }
@ -1721,7 +1721,7 @@ public:
            return FC_CONTINUE;
        case l_undef:
            TRACE("arith", tout << "check feasiable is undef\n";);
-            return m.canceled() ? FC_CONTINUE : FC_GIVEUP;
+            return m.inc() ? FC_CONTINUE : FC_GIVEUP;
        default:
            UNREACHABLE();
            break;
@ -2019,7 +2019,7 @@ public:

    lbool check_lia() {
        TRACE("arith",);
-        if (m.canceled()) {
+        if (!m.inc()) {
            TRACE("arith", tout << "canceled\n";);
            return l_undef;
        }
@ -2177,7 +2177,7 @@ public:

    lbool check_nra() {
        m_use_nra_model = false;
-        if (m.canceled()) {
+        if (!m.inc()) {
            TRACE("arith", tout << "canceled\n";);
            return l_undef;
        }
@ -2259,7 +2259,7 @@ public:
        }

        lbool lbl = make_feasible();
-        if (m.canceled())
+        if (!m.inc())
            return;
        
        switch(lbl) {
@ -2297,7 +2297,7 @@ public:

        lp().propagate_bounds_for_touched_rows(bp);

-        if (m.canceled()) {
+        if (!m.inc()) {
            return;
        }

@ -2305,7 +2305,7 @@ public:
            get_infeasibility_explanation_and_set_conflict();
        }
        else {
-            for (unsigned i = 0; !m.canceled() && !ctx().inconsistent() && i < bp.m_ibounds.size(); ++i) {
+            for (unsigned i = 0; m.inc() && !ctx().inconsistent() && i < bp.m_ibounds.size(); ++i) {
                propagate_lp_solver_bound(bp.m_ibounds[i]);
            }
        }
@ -3398,7 +3398,7 @@ public:
        else {
            rational r = get_value(v);
            TRACE("arith", tout << mk_pp(o, m) << " v" << v << " := " << r << "\n";);
-            SASSERT("integer variables should have integer values: " && (!a.is_int(o) || r.is_int() || m.canceled()));
+            SASSERT("integer variables should have integer values: " && (!a.is_int(o) || r.is_int() || m.limit().get_cancel_flag()));
            if (a.is_int(o) && !r.is_int()) r = floor(r);
            return alloc(expr_wrapper_proc, m_factory->mk_value(r,  m.get_sort(o)));
        }
--- a/src/solver/combined_solver.cpp
+++ b/src/solver/combined_solver.cpp
@ -191,7 +191,7 @@ public:
            return m_solver2->get_consequences(asms, vars, consequences);
        }
        catch (z3_exception& ex) {
-            if (get_manager().canceled()) {
+            if (!get_manager().inc()) {
                throw;
            }
            else {
@ -217,7 +217,7 @@ public:
            if (m_inc_timeout == UINT_MAX) {
                IF_VERBOSE(PS_VB_LVL, verbose_stream() << "(combined-solver \"using solver 2 (without a timeout)\")\n";);            
                lbool r = m_solver2->check_sat_core(num_assumptions, assumptions);
-                if (r != l_undef || !use_solver1_when_undef() || get_manager().canceled()) {
+                if (r != l_undef || !use_solver1_when_undef() || !get_manager().inc()) {
                    return r;
                }
            }
--- a/src/solver/parallel_tactic.cpp
+++ b/src/solver/parallel_tactic.cpp
@ -321,7 +321,7 @@ class parallel_tactic : public tactic {
        }

        bool canceled() { 
-            return m_giveup || m().canceled();
+            return m_giveup ||! m().inc();
        }

        std::ostream& display(std::ostream& out) {
@ -634,7 +634,7 @@ private:
                cube_and_conquer(*st);
                collect_statistics(*st);
                m_queue.task_done(st);
-                if (st->m().canceled()) m_queue.shutdown();
+                if (!st->m().inc()) m_queue.shutdown();
                IF_VERBOSE(1, display(verbose_stream()););
                dealloc(st);
            }
@ -748,7 +748,7 @@ public:
            g->assert_expr(m.mk_false(), pr, lcore);            
            break;
        case l_undef:
-            if (m.canceled()) {
+            if (!m.inc()) {
                throw tactic_exception(Z3_CANCELED_MSG);
            }
            break;
--- a/src/solver/solver.cpp
+++ b/src/solver/solver.cpp
@ -89,7 +89,7 @@ lbool solver::get_consequences(expr_ref_vector const& asms, expr_ref_vector cons
        return get_consequences_core(asms, vars, consequences);
    }
    catch (z3_exception& ex) {
-        if (asms.get_manager().canceled()) {
+        if (!asms.get_manager().inc()) {
            set_reason_unknown(Z3_CANCELED_MSG);
            return l_undef;
        }
@ -335,7 +335,7 @@ lbool solver::check_sat(unsigned num_assumptions, expr * const * assumptions) {
        }
        throw;
    }
-    if (r == l_undef && get_manager().canceled()) {
+    if (r == l_undef && !get_manager().inc()) {
        dump_state(num_assumptions, assumptions);        
    }
    return r;
--- a/src/solver/solver2tactic.cpp
+++ b/src/solver/solver2tactic.cpp
@ -153,7 +153,7 @@ public:
            break;
        }
        case l_undef:
-            if (m.canceled()) {
+            if (!m.inc()) {
                throw tactic_exception(Z3_CANCELED_MSG);
            }
            model_converter_ref mc;
--- a/src/tactic/aig/aig.cpp
+++ b/src/tactic/aig/aig.cpp
@ -126,7 +126,7 @@ struct aig_manager::imp {
    void checkpoint() {
        if (memory::get_allocation_size() > m_max_memory)
            throw aig_exception(TACTIC_MAX_MEMORY_MSG);
-        if (m().canceled())
+        if (!m().inc())
            throw aig_exception(m().limit().get_cancel_msg());
    }

--- a/src/tactic/arith/arith_bounds_tactic.cpp
+++ b/src/tactic/arith/arith_bounds_tactic.cpp
@ -33,9 +33,7 @@ struct arith_bounds_tactic : public tactic {
    }
    
    void checkpoint() {
-        if (m.canceled()) {
-            throw tactic_exception(m.limit().get_cancel_msg());
-        }
+        tactic::checkpoint(m);
    }
    
    
--- a/src/tactic/arith/degree_shift_tactic.cpp
+++ b/src/tactic/arith/degree_shift_tactic.cpp
@ -97,7 +97,7 @@ class degree_shift_tactic : public tactic {


        void checkpoint() {
-            if (m.canceled())
+            if (!m.inc())
                throw tactic_exception(m.limit().get_cancel_msg());
        }

--- a/src/tactic/arith/diff_neq_tactic.cpp
+++ b/src/tactic/arith/diff_neq_tactic.cpp
@ -288,7 +288,7 @@ class diff_neq_tactic : public tactic {
            init_forbidden();
            unsigned nvars = num_vars();
            while (m_stack.size() < nvars) {
-                if (m.canceled())
+                if (!m.inc())
                    throw tactic_exception(m.limit().get_cancel_msg());
                TRACE("diff_neq_tactic", display_model(tout););
                var x = m_stack.size();
--- a/src/tactic/arith/fm_tactic.cpp
+++ b/src/tactic/arith/fm_tactic.cpp
@ -198,7 +198,8 @@ class fm_tactic : public tactic {
                clauses::iterator it  = m_clauses[i].begin();
                clauses::iterator end = m_clauses[i].end();
                for (; it != end; ++it) {
-                    if (m.canceled()) throw tactic_exception(m.limit().get_cancel_msg());
+                    if (!m.inc()) 
+                        throw tactic_exception(m.limit().get_cancel_msg());
                    switch (process(x, *it, u, *md, val)) {
                    case NONE: 
                        TRACE("fm_mc", tout << "no bound for:\n" << mk_ismt2_pp(*it, m) << "\n";);
@ -1542,7 +1543,7 @@ class fm_tactic : public tactic {
        }
        
        void checkpoint() {
-            if (m.canceled())
+            if (!m.inc())
                throw tactic_exception(m.limit().get_cancel_msg());
            if (memory::get_allocation_size() > m_max_memory)
                throw tactic_exception(TACTIC_MAX_MEMORY_MSG);
--- a/src/tactic/arith/lia2card_tactic.cpp
+++ b/src/tactic/arith/lia2card_tactic.cpp
@ -164,7 +164,7 @@ public:
    }

    void checkpoint() {
-        if (m.canceled()) {
+        if (!m.inc()) {
            throw tactic_exception(m.limit().get_cancel_msg());
        }
    }
--- a/src/tactic/bv/bv_size_reduction_tactic.cpp
+++ b/src/tactic/bv/bv_size_reduction_tactic.cpp
@ -171,7 +171,7 @@ public:
    }
    
    void checkpoint() {
-        if (m.canceled())
+        if (!m.inc())
            throw tactic_exception(m.limit().get_cancel_msg());
    }
    
--- a/src/tactic/bv/bvarray2uf_tactic.cpp
+++ b/src/tactic/bv/bvarray2uf_tactic.cpp
@ -48,7 +48,7 @@ class bvarray2uf_tactic : public tactic {


        void checkpoint() {
-            if (m_manager.canceled())
+            if (!m_manager.inc())
                throw tactic_exception(m_manager.limit().get_cancel_msg());
        }

--- a/src/tactic/core/cofactor_elim_term_ite.cpp
+++ b/src/tactic/core/cofactor_elim_term_ite.cpp
@ -33,8 +33,7 @@ struct cofactor_elim_term_ite::imp {
    void checkpoint() { 
        if (memory::get_allocation_size() > m_max_memory)
            throw tactic_exception(TACTIC_MAX_MEMORY_MSG);
-        if (m.canceled())
-            throw tactic_exception(m.limit().get_cancel_msg());
+        tactic::checkpoint(m);
    }

    // Collect atoms that contain term if-then-else
--- a/src/tactic/core/ctx_simplify_tactic.cpp
+++ b/src/tactic/core/ctx_simplify_tactic.cpp
@ -203,8 +203,7 @@ struct ctx_simplify_tactic::imp {
    void checkpoint() {
        if (memory::get_allocation_size() > m_max_memory)
            throw tactic_exception(TACTIC_MAX_MEMORY_MSG);
-        if (m.canceled())
-            throw tactic_exception(m.limit().get_cancel_msg());
+        tactic::checkpoint(m);
    }

    bool shared(expr * t) const {
--- a/src/tactic/core/occf_tactic.cpp
+++ b/src/tactic/core/occf_tactic.cpp
@ -35,8 +35,7 @@ class occf_tactic : public tactic {
        }

        void checkpoint() {
-            if (m.canceled())
-                throw tactic_exception(TACTIC_CANCELED_MSG);
+            tactic::checkpoint(m);
        }

        bool is_literal(expr * t) const {
--- a/src/tactic/core/reduce_args_tactic.cpp
+++ b/src/tactic/core/reduce_args_tactic.cpp
@ -112,8 +112,7 @@ struct reduce_args_tactic::imp {
    }

    void checkpoint() { 
-        if (m_manager.canceled())
-            throw tactic_exception(m_manager.limit().get_cancel_msg());
+        tactic::checkpoint(m_manager);
    }
    
    struct find_non_candidates_proc {
--- a/src/tactic/core/reduce_invertible_tactic.cpp
+++ b/src/tactic/core/reduce_invertible_tactic.cpp
@ -101,8 +101,7 @@ public:

 private:
    void checkpoint() { 
-        if (m.canceled())
-            throw tactic_exception(m.limit().get_cancel_msg());
+        tactic::checkpoint(m);
    }

    bool is_bv_neg(expr * e) {
--- a/src/tactic/core/solve_eqs_tactic.cpp
+++ b/src/tactic/core/solve_eqs_tactic.cpp
@ -86,8 +86,7 @@ class solve_eqs_tactic : public tactic {
        }
                
        void checkpoint() {
-            if (m().canceled())
-                throw tactic_exception(m().limit().get_cancel_msg());
+            tactic::checkpoint(m());
        }
        
        // Check if the number of occurrences of t is below the specified threshold :solve-eqs-max-occs
--- a/src/tactic/core/tseitin_cnf_tactic.cpp
+++ b/src/tactic/core/tseitin_cnf_tactic.cpp
@ -786,8 +786,7 @@ class tseitin_cnf_tactic : public tactic {
        
        
        void checkpoint() {
-            if (m.canceled())
-                throw tactic_exception(TACTIC_CANCELED_MSG);
+            tactic::checkpoint(m);
            if (memory::get_allocation_size() > m_max_memory)
                throw tactic_exception(TACTIC_MAX_MEMORY_MSG);
        }
--- a/src/tactic/fd_solver/bounded_int2bv_solver.cpp
+++ b/src/tactic/fd_solver/bounded_int2bv_solver.cpp
@ -329,7 +329,7 @@ private:
            for (expr* a : m_assertions) {
                sub(a, fml1);
                m_rewriter(fml1, fml2, proof);
-                if (m.canceled()) {
+                if (!m.inc()) {
                    m_rewriter.reset();
                    return;
                }
--- a/src/tactic/fd_solver/smtfd_solver.cpp
+++ b/src/tactic/fd_solver/smtfd_solver.cpp
@ -1815,9 +1815,7 @@ namespace smtfd {
        }

        void checkpoint() {
-            if (m.canceled()) {
-                throw tactic_exception(m.limit().get_cancel_msg());
-            }
+            tactic::checkpoint(m);
        }

        expr* rep(expr* e) { return m_abs.rep(e); }
--- a/src/tactic/sls/sls_engine.cpp
+++ b/src/tactic/sls/sls_engine.cpp
@ -93,8 +93,7 @@ void sls_engine::collect_statistics(statistics& st) const {
 }

 void sls_engine::checkpoint() {
-    if (m_manager.canceled())
-        throw tactic_exception(m_manager.limit().get_cancel_msg());
+    tactic::checkpoint(m_manager);
 }

 bool sls_engine::full_eval(model & mdl) {
--- a/src/tactic/tactic.cpp
+++ b/src/tactic/tactic.cpp
@ -246,3 +246,7 @@ void fail_if_has_quantifiers(char const* tactic_name, goal_ref const& g) {
        }
 }

+void tactic::checkpoint(ast_manager& m) {
+    if (!m.inc())
+        throw tactic_exception(m.limit().get_cancel_msg());
+}
--- a/src/tactic/tactic.h
+++ b/src/tactic/tactic.h
@ -74,6 +74,9 @@ public:

    // translate tactic to the given manager
    virtual tactic * translate(ast_manager & m) = 0;
+
+    static void checkpoint(ast_manager& m);
+
 protected:
    friend class nary_tactical;
    friend class binary_tactical;
--- a/src/tactic/ufbv/quasi_macros_tactic.cpp
+++ b/src/tactic/ufbv/quasi_macros_tactic.cpp
@ -57,8 +57,7 @@ class quasi_macros_tactic : public tactic {
            }

            do { 
-                if (m().canceled())
-                    throw tactic_exception(m().limit().get_cancel_msg());
+                tactic::checkpoint(m());
            } 
            while (qm(forms, proofs, deps));