From dd1ca8f6bd1e2bc8dada167eb0056cfd4abc3dd1 Mon Sep 17 00:00:00 2001
From: Nikolaj Bjorner <nbjorner@microsoft.com>
Date: Tue, 29 Nov 2022 16:36:02 +0700
Subject: [PATCH] move qhead to attribute on the state instead of the
 simplifier,

- add sat.smt option to enable the new incremental core (it is not ready for mainstream consumption as cloning and other features are not implemented and it hasn't been tested in any detail yet).
- move "name" into attribute on simplifier so it can be reused for diagnostics by the seq-simplifier.
---
 src/ast/simplifiers/bit_blaster.cpp           |  4 +--
 src/ast/simplifiers/bit_blaster.h             |  2 +-
 src/ast/simplifiers/bv_slice.cpp              |  5 ++-
 src/ast/simplifiers/bv_slice.h                |  2 +-
 src/ast/simplifiers/card2bv.cpp               |  4 +--
 src/ast/simplifiers/card2bv.h                 |  1 +
 src/ast/simplifiers/dependent_expr_state.h    | 18 +++++++---
 src/ast/simplifiers/elim_unconstrained.cpp    |  7 ++--
 src/ast/simplifiers/elim_unconstrained.h      |  2 ++
 src/ast/simplifiers/eliminate_predicates.cpp  |  6 ++--
 src/ast/simplifiers/eliminate_predicates.h    |  2 ++
 src/ast/simplifiers/euf_completion.cpp        |  6 ++--
 src/ast/simplifiers/euf_completion.h          |  1 +
 src/ast/simplifiers/max_bv_sharing.cpp        |  5 +--
 src/ast/simplifiers/propagate_values.cpp      |  7 ++--
 src/ast/simplifiers/propagate_values.h        |  1 +
 src/ast/simplifiers/rewriter_simplifier.h     |  5 +--
 src/ast/simplifiers/seq_simplifier.h          | 36 +++++++++++++++++--
 src/ast/simplifiers/solve_context_eqs.cpp     |  2 +-
 src/ast/simplifiers/solve_eqs.cpp             |  6 ++--
 src/ast/simplifiers/solve_eqs.h               |  2 ++
 src/sat/sat_params.pyg                        |  9 ++---
 src/sat/sat_solver/sat_smt_preprocess.cpp     |  2 +-
 src/sat/sat_solver/sat_smt_solver.cpp         | 30 ++++++++--------
 src/sat/smt/q_mbi.cpp                         |  2 +-
 src/sat/tactic/goal2sat.cpp                   |  2 +-
 src/solver/solver.h                           |  2 +-
 src/tactic/arith/card2bv_tactic.h             |  2 +-
 src/tactic/bv/bv_slice_tactic.cpp             |  2 +-
 src/tactic/bv/max_bv_sharing_tactic.h         |  2 +-
 src/tactic/core/elim_uncnstr2_tactic.h        |  2 +-
 src/tactic/core/eliminate_predicates_tactic.h |  4 +--
 src/tactic/core/euf_completion_tactic.cpp     |  2 +-
 src/tactic/core/propagate_values2_tactic.h    |  2 +-
 src/tactic/core/solve_eqs_tactic.h            |  2 +-
 src/tactic/dependent_expr_state_tactic.h      | 12 +++----
 src/tactic/portfolio/smt_strategic_solver.cpp | 16 ++++++---
 37 files changed, 132 insertions(+), 85 deletions(-)

diff --git a/src/ast/simplifiers/bit_blaster.cpp b/src/ast/simplifiers/bit_blaster.cpp
index 218765d28..dc086c628 100644
--- a/src/ast/simplifiers/bit_blaster.cpp
+++ b/src/ast/simplifiers/bit_blaster.cpp
@@ -37,7 +37,7 @@ void bit_blaster::reduce() {
     expr_ref   new_curr(m);
     proof_ref  new_pr(m);
     bool change = false;
-    for (unsigned idx = m_qhead; idx < m_fmls.size(); idx++) {
+    for (unsigned idx = m_fmls.qhead(); idx < m_fmls.size(); idx++) {
         if (m_fmls.inconsistent())
             break;
         auto [curr, d] = m_fmls[idx]();
@@ -60,8 +60,6 @@ void bit_blaster::reduce() {
             m_fmls.model_trail().push(f, v, nullptr, {});
     }
     m_rewriter.cleanup();
-    
-    advance_qhead();
 }
 
 
diff --git a/src/ast/simplifiers/bit_blaster.h b/src/ast/simplifiers/bit_blaster.h
index 70446918b..231a1ca68 100644
--- a/src/ast/simplifiers/bit_blaster.h
+++ b/src/ast/simplifiers/bit_blaster.h
@@ -33,7 +33,7 @@ public:
         m_rewriter(m, p) {
         updt_params(p);
     }
-
+    char const* name() const override { return "bit-blaster"; }
     void updt_params(params_ref const & p) override;
     void collect_param_descrs(param_descrs & r) override;
     void reduce() override;
diff --git a/src/ast/simplifiers/bv_slice.cpp b/src/ast/simplifiers/bv_slice.cpp
index 995231b34..14d6edb99 100644
--- a/src/ast/simplifiers/bv_slice.cpp
+++ b/src/ast/simplifiers/bv_slice.cpp
@@ -24,11 +24,10 @@ namespace bv {
     void slice::reduce() {
         process_eqs();
         apply_subst();
-        advance_qhead();
     }
 
     void slice::process_eqs() {
-        for (unsigned i = m_qhead; i < m_fmls.size(); ++i) {
+        for (unsigned i = m_fmls.qhead(); i < m_fmls.size(); ++i) {
             auto const [f, d] = m_fmls[i]();
             process_eq(f);
         }  
@@ -137,7 +136,7 @@ namespace bv {
         expr_ref_vector cache(m), pin(m);
         ptr_vector<expr> todo, args;
         expr* c;
-        for (unsigned i = m_qhead; i < m_fmls.size(); ++i) {
+        for (unsigned i = m_fmls.qhead(); i < m_fmls.size(); ++i) {
             auto const [f, d] = m_fmls[i]();
             todo.push_back(f);
             pin.push_back(f);
diff --git a/src/ast/simplifiers/bv_slice.h b/src/ast/simplifiers/bv_slice.h
index cc0f48cfc..3bf514ac3 100644
--- a/src/ast/simplifiers/bv_slice.h
+++ b/src/ast/simplifiers/bv_slice.h
@@ -47,7 +47,7 @@ namespace bv {
     public:
 
         slice(ast_manager& m, dependent_expr_state& fmls) : dependent_expr_simplifier(m, fmls), m_bv(m), m_rewriter(m) {}
-
+        char const* name() const override { return "bv-slice"; }
         void push() override { dependent_expr_simplifier::push(); }
         void pop(unsigned n) override { dependent_expr_simplifier::pop(n); }
         void reduce() override;
diff --git a/src/ast/simplifiers/card2bv.cpp b/src/ast/simplifiers/card2bv.cpp
index 44bc8e589..3feb86474 100644
--- a/src/ast/simplifiers/card2bv.cpp
+++ b/src/ast/simplifiers/card2bv.cpp
@@ -29,7 +29,7 @@ void card2bv::reduce() {
                         
     expr_ref new_f1(m), new_f2(m);
     proof_ref new_pr(m);
-    for (unsigned idx = m_qhead; !m_fmls.inconsistent() && idx < m_fmls.size(); idx++) {
+    for (unsigned idx = m_fmls.qhead(); !m_fmls.inconsistent() && idx < m_fmls.size(); idx++) {
         auto [f, d] = m_fmls[idx]();
         rw1(f, new_f1);        
         rw2(false, new_f1, new_f2, new_pr);        
@@ -48,8 +48,6 @@ void card2bv::reduce() {
     func_decl_ref_vector const& fns = rw2.fresh_constants();
     for (func_decl* f : fns)
         m_fmls.model_trail().hide(f);    
-
-     advance_qhead();
 }
 
 void card2bv::collect_statistics(statistics& st) const {
diff --git a/src/ast/simplifiers/card2bv.h b/src/ast/simplifiers/card2bv.h
index e089fa84c..4c081c8cd 100644
--- a/src/ast/simplifiers/card2bv.h
+++ b/src/ast/simplifiers/card2bv.h
@@ -34,6 +34,7 @@ class card2bv : public dependent_expr_simplifier {
 
 public:
     card2bv(ast_manager& m, params_ref const& p, dependent_expr_state& fmls);
+    char const* name() const override { return "card2bv"; }
     void reduce() override;
     void collect_statistics(statistics& st) const override;
     void reset_statistics() override { m_stats.reset(); }
diff --git a/src/ast/simplifiers/dependent_expr_state.h b/src/ast/simplifiers/dependent_expr_state.h
index 90b95ab7d..54ee5626b 100644
--- a/src/ast/simplifiers/dependent_expr_state.h
+++ b/src/ast/simplifiers/dependent_expr_state.h
@@ -41,6 +41,7 @@ Author:
    abstract interface to state updated by simplifiers.
  */
 class dependent_expr_state {
+    unsigned m_qhead = 0;
 public:
     virtual ~dependent_expr_state() {}
     virtual unsigned size() const = 0;
@@ -53,8 +54,15 @@ public:
     trail_stack    m_trail;
     void push() { m_trail.push_scope(); }
     void pop(unsigned n) { m_trail.pop_scope(n); }
-
-
+    unsigned qhead() const { return m_qhead; }
+    void advance_qhead() { m_qhead = size(); }
+    unsigned num_exprs() {
+        expr_fast_mark1 visited;
+        unsigned r = 0;
+        for (unsigned i = 0; i < size(); i++) 
+            r += get_num_exprs((*this)[i].fml(), visited);
+        return r;
+    }
 };
 
 /**
@@ -65,14 +73,13 @@ protected:
     ast_manager& m;
     dependent_expr_state& m_fmls;
     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(); }
 
-    void advance_qhead() { if (num_scopes() > 0) m_trail.push(value_trail(m_qhead)); m_qhead = m_fmls.size(); }
 public:
     dependent_expr_simplifier(ast_manager& m, dependent_expr_state& s) : m(m), m_fmls(s), m_trail(s.m_trail) {}
     virtual ~dependent_expr_simplifier() {}
+    virtual char const* name() const = 0;
     virtual void push() { }
     virtual void pop(unsigned n) { }
     virtual void reduce() = 0;
@@ -80,7 +87,8 @@ public:
     virtual void reset_statistics() {}
     virtual void updt_params(params_ref const& p) {}
     virtual void collect_param_descrs(param_descrs& r) {}
-    unsigned qhead() const { return m_qhead; }
+    ast_manager& get_manager() { return m; }
+    dependent_expr_state& get_fmls() { return m_fmls; }
 };
 
 /**
diff --git a/src/ast/simplifiers/elim_unconstrained.cpp b/src/ast/simplifiers/elim_unconstrained.cpp
index ac5cc339d..93a84dba6 100644
--- a/src/ast/simplifiers/elim_unconstrained.cpp
+++ b/src/ast/simplifiers/elim_unconstrained.cpp
@@ -138,7 +138,7 @@ void elim_unconstrained::init_nodes() {
 
     // freeze subterms before the already processed head
     terms.reset();
-    for (unsigned i = 0; i < m_qhead; ++i)
+    for (unsigned i = 0; i < m_fmls.qhead(); ++i)
         terms.push_back(m_fmls[i].fml());
     for (expr* e : subterms::all(terms))
         m_frozen.mark(e, true);    
@@ -216,7 +216,7 @@ void elim_unconstrained::gc(expr* t) {
  */
 void elim_unconstrained::reconstruct_terms() {
     expr_ref_vector terms(m);
-    for (unsigned i = m_qhead; i < m_fmls.size(); ++i)
+    for (unsigned i = m_fmls.qhead(); i < m_fmls.size(); ++i)
         terms.push_back(m_fmls[i].fml());    
 
     for (expr* e : subterms_postorder::all(terms)) {
@@ -250,7 +250,7 @@ void elim_unconstrained::reconstruct_terms() {
 void elim_unconstrained::assert_normalized(vector<dependent_expr>& old_fmls) {
 
     unsigned sz = m_fmls.size();
-    for (unsigned i = m_qhead; i < sz; ++i) {
+    for (unsigned i = m_fmls.qhead(); i < sz; ++i) {
         auto [f, d] = m_fmls[i]();
         node& n = get_node(f);
         expr* g = n.m_term;
@@ -302,5 +302,4 @@ void elim_unconstrained::reduce() {
     vector<dependent_expr> old_fmls;
     assert_normalized(old_fmls);
     update_model_trail(*mc, old_fmls);
-    advance_qhead();
 }
diff --git a/src/ast/simplifiers/elim_unconstrained.h b/src/ast/simplifiers/elim_unconstrained.h
index 89f28fe33..b66d0b727 100644
--- a/src/ast/simplifiers/elim_unconstrained.h
+++ b/src/ast/simplifiers/elim_unconstrained.h
@@ -71,6 +71,8 @@ public:
 
     elim_unconstrained(ast_manager& m, dependent_expr_state& fmls);
 
+    char const* name() const override { return "elim-unconstrained"; }
+
     void reduce() override;
 
     void collect_statistics(statistics& st) const override { st.update("elim-unconstrained", m_stats.m_num_eliminated); }
diff --git a/src/ast/simplifiers/eliminate_predicates.cpp b/src/ast/simplifiers/eliminate_predicates.cpp
index 6d1288c5d..fa615048f 100644
--- a/src/ast/simplifiers/eliminate_predicates.cpp
+++ b/src/ast/simplifiers/eliminate_predicates.cpp
@@ -501,7 +501,7 @@ void eliminate_predicates::reduce_definitions() {
     for (auto const& [k, v] : m_macros) 
         macro_expander.insert(v->m_head, v->m_def, v->m_dep);
     
-    for (unsigned i = m_qhead; i < m_fmls.size(); ++i) {
+    for (unsigned i = m_fmls.qhead(); i < m_fmls.size(); ++i) {
         auto [f, d] = m_fmls[i]();
         expr_ref fml(f, m), new_fml(m);
         expr_dependency_ref dep(m);
@@ -779,7 +779,7 @@ eliminate_predicates::clause* eliminate_predicates::init_clause(expr* f, expr_de
 * eliminations.
 */
 void eliminate_predicates::init_clauses() {
-    for (unsigned i = 0; i < m_qhead; ++i)
+    for (unsigned i = 0; i < m_fmls.qhead(); ++i)
         m_to_exclude.push_back(m_fmls[i].fml());
     recfun::util rec(m);
     if (rec.has_rec_defs()) 
@@ -788,7 +788,7 @@ void eliminate_predicates::init_clauses() {
     
     process_to_exclude(m_disable_macro);
 
-    for (unsigned i = m_qhead; i < m_fmls.size(); ++i) {
+    for (unsigned i = m_fmls.qhead(); i < m_fmls.size(); ++i) {
         clause* cl = init_clause(i);
         add_use_list(*cl);
         m_clauses.push_back(cl);
diff --git a/src/ast/simplifiers/eliminate_predicates.h b/src/ast/simplifiers/eliminate_predicates.h
index 6afd0886a..ca4110e99 100644
--- a/src/ast/simplifiers/eliminate_predicates.h
+++ b/src/ast/simplifiers/eliminate_predicates.h
@@ -129,6 +129,8 @@ public:
     eliminate_predicates(ast_manager& m, dependent_expr_state& fmls);
 
     ~eliminate_predicates() override { reset(); }
+
+    char const* name() const override { return "elim-predicates"; }
     
     void reduce() override;
 
diff --git a/src/ast/simplifiers/euf_completion.cpp b/src/ast/simplifiers/euf_completion.cpp
index 5056d818c..f077f1918 100644
--- a/src/ast/simplifiers/euf_completion.cpp
+++ b/src/ast/simplifiers/euf_completion.cpp
@@ -80,7 +80,7 @@ namespace euf {
                 m_nodes_to_canonize.push_back(ch);
         };
 
-        for (unsigned i = m_qhead; i < sz; ++i) {
+        for (unsigned i = m_fmls.qhead(); i < sz; ++i) {
             expr* x, * y;
             auto [f, d] = m_fmls[i]();
             if (m.is_eq(f, x, y)) {
@@ -114,7 +114,7 @@ namespace euf {
         }
 
         unsigned sz = m_fmls.size();
-        for (unsigned i = m_qhead; i < sz; ++i) {
+        for (unsigned i = m_fmls.qhead(); i < sz; ++i) {
             auto [f, d] = m_fmls[i]();
             
             expr_dependency_ref dep(d, m);
@@ -127,8 +127,6 @@ namespace euf {
             }
             CTRACE("euf_completion", g != f, tout << mk_bounded_pp(f, m) << " -> " << mk_bounded_pp(g, m) << "\n");
         }
-        if (!m_has_new_eq)
-            advance_qhead();
     }
 
     bool completion::is_new_eq(expr* a, expr* b) {
diff --git a/src/ast/simplifiers/euf_completion.h b/src/ast/simplifiers/euf_completion.h
index f02e33245..da0fb7276 100644
--- a/src/ast/simplifiers/euf_completion.h
+++ b/src/ast/simplifiers/euf_completion.h
@@ -58,6 +58,7 @@ namespace euf {
         expr_dependency* explain_conflict();
     public:
         completion(ast_manager& m, dependent_expr_state& fmls);
+        char const* name() const override { return "euf-reduce"; }
         void push() override { m_egraph.push(); dependent_expr_simplifier::push(); }
         void pop(unsigned n) override { dependent_expr_simplifier::pop(n); m_egraph.pop(n); }
         void reduce() override;
diff --git a/src/ast/simplifiers/max_bv_sharing.cpp b/src/ast/simplifiers/max_bv_sharing.cpp
index 3003a47a0..4744c473c 100644
--- a/src/ast/simplifiers/max_bv_sharing.cpp
+++ b/src/ast/simplifiers/max_bv_sharing.cpp
@@ -250,10 +250,12 @@ public:
                  "(default: 128) maximum number of arguments (per application) that will be considered by the greedy (quadratic) heuristic.");
     }
 
+    char const* name() const override { return "max-bv-sharing"; }
+
     void reduce() override {
         expr_ref   new_curr(m);
         proof_ref  new_pr(m);
-        for (unsigned idx = m_qhead; idx < m_fmls.size() && !m_fmls.inconsistent(); idx++) {
+        for (unsigned idx = m_fmls.qhead(); idx < m_fmls.size() && !m_fmls.inconsistent(); idx++) {
             auto [curr, d] = m_fmls[idx]();
             m_rw(curr, new_curr, new_pr);
             // Proof reconstruction: new_pr = m.mk_modus_ponens(old_pr, new_pr);
@@ -261,7 +263,6 @@ public:
             m_fmls.update(idx, dependent_expr(m, new_curr, d));            
         }
         m_rw.cfg().cleanup();
-        advance_qhead();
     }        
 };
 
diff --git a/src/ast/simplifiers/propagate_values.cpp b/src/ast/simplifiers/propagate_values.cpp
index 6d6bc976f..2572cc310 100644
--- a/src/ast/simplifiers/propagate_values.cpp
+++ b/src/ast/simplifiers/propagate_values.cpp
@@ -78,7 +78,7 @@ void propagate_values::reduce() {
         subst.reset();
         m_rewriter.reset();
         m_rewriter.set_substitution(&subst);
-        for (unsigned i = 0; i < m_qhead; ++i)
+        for (unsigned i = 0; i < m_fmls.qhead(); ++i)
             add_sub(m_fmls[i]);
     };
     
@@ -86,10 +86,10 @@ void propagate_values::reduce() {
     for (unsigned r = 0; r < m_max_rounds && rw != m_stats.m_num_rewrites; ++r) {            
         rw = m_stats.m_num_rewrites;
         init_sub();
-        for (unsigned i = m_qhead; i < m_fmls.size() && !m_fmls.inconsistent(); ++i)
+        for (unsigned i = m_fmls.qhead(); i < m_fmls.size() && !m_fmls.inconsistent(); ++i)
             process_fml(i);
         init_sub();
-        for (unsigned i = m_fmls.size(); i-- > m_qhead && !m_fmls.inconsistent();)
+        for (unsigned i = m_fmls.size(); i-- > m_fmls.qhead() && !m_fmls.inconsistent();)
             process_fml(i);
         if (subst.empty())
             break;
@@ -97,7 +97,6 @@ void propagate_values::reduce() {
     
     m_rewriter.set_substitution(nullptr);        
     m_rewriter.reset();
-    advance_qhead();
 }
 
 void propagate_values::collect_statistics(statistics& st) const {
diff --git a/src/ast/simplifiers/propagate_values.h b/src/ast/simplifiers/propagate_values.h
index d263377b1..9ad59d1b3 100644
--- a/src/ast/simplifiers/propagate_values.h
+++ b/src/ast/simplifiers/propagate_values.h
@@ -37,6 +37,7 @@ class propagate_values : public dependent_expr_simplifier {
 
 public:
     propagate_values(ast_manager& m, params_ref const& p, dependent_expr_state& fmls);
+    char const* name() const override { return "propagate-values2"; }
     void reduce() override;
     void collect_statistics(statistics& st) const override;
     void reset_statistics() override { m_stats.reset(); }
diff --git a/src/ast/simplifiers/rewriter_simplifier.h b/src/ast/simplifiers/rewriter_simplifier.h
index 23ebb4f84..f956ec808 100644
--- a/src/ast/simplifiers/rewriter_simplifier.h
+++ b/src/ast/simplifiers/rewriter_simplifier.h
@@ -33,12 +33,14 @@ public:
         m_rewriter(m) {
         updt_params(p);
     }
+
+    char const* name() const override { return "simplifier"; }
         
     void reduce() override {
         m_num_steps = 0;
         expr_ref   new_curr(m);
         proof_ref  new_pr(m);
-        for (unsigned idx = m_qhead; idx < m_fmls.size(); idx++) {
+        for (unsigned idx = m_fmls.qhead(); idx < m_fmls.size(); idx++) {
             if (m_fmls.inconsistent())
                 break;
             auto d = m_fmls[idx];
@@ -46,7 +48,6 @@ public:
             m_num_steps += m_rewriter.get_num_steps();
             m_fmls.update(idx, dependent_expr(m, new_curr, d.dep()));            
         }
-        advance_qhead();
     }
     void collect_statistics(statistics& st) const override { st.update("simplifier", m_num_steps); }
     void reset_statistics() override { m_num_steps = 0; }
diff --git a/src/ast/simplifiers/seq_simplifier.h b/src/ast/simplifiers/seq_simplifier.h
index 0d5483b71..0fa5990dd 100644
--- a/src/ast/simplifiers/seq_simplifier.h
+++ b/src/ast/simplifiers/seq_simplifier.h
@@ -17,16 +17,46 @@ Author:
 
 #pragma once
 
+#include "util/stopwatch.h"
 #include "ast/simplifiers/dependent_expr_state.h"
 
 
 class seq_simplifier : public dependent_expr_simplifier {
     scoped_ptr_vector<dependent_expr_simplifier> m_simplifiers;
 
+    struct collect_stats {
+        stopwatch       m_watch;
+        double          m_start_memory = 0;
+        dependent_expr_simplifier& s;
+        collect_stats(dependent_expr_simplifier& s) : 
+            m_start_memory(static_cast<double>(memory::get_allocation_size()) / static_cast<double>(1024 * 1024)), 
+            s(s) {
+            m_watch.start();
+        }
+        ~collect_stats() {
+            m_watch.stop();
+            double end_memory = static_cast<double>(memory::get_allocation_size()) / static_cast<double>(1024 * 1024);
+            IF_VERBOSE(10,
+                statistics st;
+                verbose_stream() << "(" << s.name()
+                << " :num-exprs " << s.get_fmls().num_exprs()
+                << " :num-asts " << s.get_manager().get_num_asts()
+                << " :time " << std::fixed << std::setprecision(2) << m_watch.get_seconds()
+                << " :before-memory " << std::fixed << std::setprecision(2) << m_start_memory
+                << " :after-memory " << std::fixed << std::setprecision(2) << end_memory
+                << ")" << "\n";
+            s.collect_statistics(st);
+            verbose_stream() << st);
+        }
+    };
+
 public:
+    
     seq_simplifier(ast_manager& m, params_ref const& p, dependent_expr_state& fmls):
         dependent_expr_simplifier(m, fmls) {
     }
+
+    char const* name() const override { return "and-then"; }
     
     void add_simplifier(dependent_expr_simplifier* s) {
         m_simplifiers.push_back(s);
@@ -36,9 +66,11 @@ public:
         for (auto* s : m_simplifiers) {
             if (m_fmls.inconsistent())
                 break;
+            if (!m.inc())
+                break;
+            collect_stats _cs(*s);
             s->reduce();
-        }
-        advance_qhead();        
+        }      
     }
     
     void collect_statistics(statistics& st) const override {
diff --git a/src/ast/simplifiers/solve_context_eqs.cpp b/src/ast/simplifiers/solve_context_eqs.cpp
index ef52d009c..7eaa8ad2f 100644
--- a/src/ast/simplifiers/solve_context_eqs.cpp
+++ b/src/ast/simplifiers/solve_context_eqs.cpp
@@ -148,7 +148,7 @@ namespace euf {
     void solve_context_eqs::collect_nested_equalities(dep_eq_vector& eqs) {
         expr_mark visited;
         unsigned sz = m_fmls.size();
-        for (unsigned i = m_solve_eqs.m_qhead; i < sz; ++i)
+        for (unsigned i = m_fmls.qhead(); i < sz; ++i)
             collect_nested_equalities(m_fmls[i], visited, eqs);
 
         if (eqs.empty())
diff --git a/src/ast/simplifiers/solve_eqs.cpp b/src/ast/simplifiers/solve_eqs.cpp
index 1bea283ac..f6055af50 100644
--- a/src/ast/simplifiers/solve_eqs.cpp
+++ b/src/ast/simplifiers/solve_eqs.cpp
@@ -34,7 +34,7 @@ namespace euf {
 
     void solve_eqs::get_eqs(dep_eq_vector& eqs) {
         for (extract_eq* ex : m_extract_plugins)
-            for (unsigned i = m_qhead; i < m_fmls.size(); ++i)
+            for (unsigned i = m_fmls.qhead(); i < m_fmls.size(); ++i)
                 ex->get_eqs(m_fmls[i], eqs);
     }
 
@@ -187,7 +187,7 @@ namespace euf {
         scoped_ptr<expr_replacer> rp = mk_default_expr_replacer(m, false);
         rp->set_substitution(m_subst.get());
 
-        for (unsigned i = m_qhead; i < m_fmls.size() && !m_fmls.inconsistent(); ++i) {
+        for (unsigned i = m_fmls.qhead(); i < m_fmls.size() && !m_fmls.inconsistent(); ++i) {
             auto [f, d] = m_fmls[i]();
             auto [new_f, new_dep] = rp->replace_with_dep(f);
             m_rewriter(new_f);
@@ -236,8 +236,6 @@ namespace euf {
             apply_subst(old_fmls);
             save_subst(old_fmls);
         }
-
-        advance_qhead();
     }
 
     void solve_eqs::save_subst(vector<dependent_expr> const& old_fmls) {
diff --git a/src/ast/simplifiers/solve_eqs.h b/src/ast/simplifiers/solve_eqs.h
index a2afd6e58..4b2905b2a 100644
--- a/src/ast/simplifiers/solve_eqs.h
+++ b/src/ast/simplifiers/solve_eqs.h
@@ -68,6 +68,8 @@ namespace euf {
 
         solve_eqs(ast_manager& m, dependent_expr_state& fmls);
 
+        char const* name() const override { return "solve-eqs"; }
+
         void reduce() override;
 
         void updt_params(params_ref const& p) override;
diff --git a/src/sat/sat_params.pyg b/src/sat/sat_params.pyg
index 20a415441..f9d7c643a 100644
--- a/src/sat/sat_params.pyg
+++ b/src/sat/sat_params.pyg
@@ -47,6 +47,7 @@ def_module_params('sat',
                           ('threads', UINT, 1, 'number of parallel threads to use'),
                           ('dimacs.core', BOOL, False, 'extract core from DIMACS benchmarks'),
                           ('drat.disable', BOOL, False, 'override anything that enables DRAT'),
+                          ('smt', BOOL, False, 'use the SAT solver based incremental SMT core'),
                           ('smt.proof.check', BOOL, False, 'check SMT proof while it is created'),
                           ('smt.proof.check_rup', BOOL, True, 'apply forward RUP proof checking'),
                           ('drat.file', SYMBOL, '', 'file to dump DRAT proofs'),
@@ -73,11 +74,11 @@ def_module_params('sat',
                           ('local_search_mode', SYMBOL, 'wsat', 'local search algorithm, either default wsat or qsat'),
                           ('local_search_dbg_flips', BOOL, False, 'write debug information for number of flips'),
                           ('binspr', BOOL, False, 'enable SPR inferences of binary propagation redundant clauses. This inprocessing step eliminates models'),
-	                  ('anf', BOOL, False, 'enable ANF based simplification in-processing'),
-	                  ('anf.delay', UINT, 2, 'delay ANF simplification by in-processing round'),
+	                      ('anf', BOOL, False, 'enable ANF based simplification in-processing'),
+	                      ('anf.delay', UINT, 2, 'delay ANF simplification by in-processing round'),
                           ('anf.exlin', BOOL, False, 'enable extended linear simplification'), 
-		          ('cut', BOOL, False, 'enable AIG based simplification in-processing'),
-	                  ('cut.delay', UINT, 2, 'delay cut simplification by in-processing round'),
+		                  ('cut', BOOL, False, 'enable AIG based simplification in-processing'),
+	                      ('cut.delay', UINT, 2, 'delay cut simplification by in-processing round'),
                           ('cut.aig',   BOOL, False, 'extract aigs (and ites) from cluases for cut simplification'),
                           ('cut.lut',   BOOL, False, 'extract luts from clauses for cut simplification'),
                           ('cut.xor',   BOOL, False, 'extract xors from clauses for cut simplification'),
diff --git a/src/sat/sat_solver/sat_smt_preprocess.cpp b/src/sat/sat_solver/sat_smt_preprocess.cpp
index 72c7c5232..f05fc098f 100644
--- a/src/sat/sat_solver/sat_smt_preprocess.cpp
+++ b/src/sat/sat_solver/sat_smt_preprocess.cpp
@@ -44,7 +44,7 @@ void init_preprocess(ast_manager& m, params_ref const& p, seq_simplifier& s, dep
     simp2_p.set_bool("flat_and_or", false);
     
     sat_params sp(p);
-    if (sp.euf()) {
+    if (sp.euf() || sp.smt()) {
         s.add_simplifier(alloc(rewriter_simplifier, m, p, st));
         s.add_simplifier(alloc(propagate_values, m, p, st));
         //
diff --git a/src/sat/sat_solver/sat_smt_solver.cpp b/src/sat/sat_solver/sat_smt_solver.cpp
index 3ea0543ec..2d95dab69 100644
--- a/src/sat/sat_solver/sat_smt_solver.cpp
+++ b/src/sat/sat_solver/sat_smt_solver.cpp
@@ -130,7 +130,7 @@ class sat_smt_solver : public solver {
     trail_stack&                m_trail;
     dependency2assumptions      m_dep;
     goal2sat                    m_goal2sat;
-    expr_ref_vector             m_assumptions, m_core, m_ors, m_aux_fmls;
+    expr_ref_vector             m_assumptions, m_core, m_ors, m_aux_fmls, m_internalized_fmls;
     atom2bool_var               m_map;
     generic_model_converter_ref m_mc;
     unsigned                    m_mc_size = 0;
@@ -140,9 +140,8 @@ class sat_smt_solver : public solver {
     // access formulas after they have been pre-processed and handled by the sat solver.
     // this allows to access the internal state of the SAT solver and carry on partial results.
     bool                        m_internalized_converted = false; // have internalized formulas been converted back
-    expr_ref_vector             m_internalized_fmls;      // formulas in internalized format
 
-    bool is_internalized() const { return m_preprocess.qhead() == m_fmls.size(); }
+    bool is_internalized() const { return m_preprocess_state.qhead() == m_fmls.size(); }
     
 public:
     sat_smt_solver(ast_manager& m, params_ref const& p):
@@ -152,16 +151,12 @@ public:
         m_trail(m_preprocess_state.m_trail),
         m_dep(m, m_trail),
         m_solver(p, m.limit()),
-        m_assumptions(m),
-        m_core(m),
-        m_ors(m),
-        m_aux_fmls(m),
+        m_assumptions(m), m_core(m), m_ors(m), m_aux_fmls(m), m_internalized_fmls(m),
         m_map(m),
-        m_internalized_fmls(m) {
+        m_mc(alloc(generic_model_converter, m, "sat-smt-solver")) {
         updt_params(p);
         init_preprocess();
         m_solver.set_incremental(true);
-        m_mc = alloc(generic_model_converter, m, "sat-smt-solver");
     }
 
     solver* translate(ast_manager& dst_m, params_ref const& p) override {
@@ -214,7 +209,7 @@ public:
         expr_ref_vector assumptions(m);
         for (unsigned i = 0; i < sz; ++i)
             assumptions.push_back(ensure_literal(_assumptions[i]));
-        TRACE("sat", tout << _assumptions << "\n";);
+        TRACE("sat", tout << assumptions << "\n";);
         lbool r = internalize_formulas();
         if (r != l_true)
             return r;
@@ -267,8 +262,7 @@ public:
     }
 
     void pop(unsigned n) override {
-        if (n > m_trail.get_num_scopes())     // allow inc_sat_solver to
-            n = m_trail.get_num_scopes();     // take over for another solver.       
+        n = std::min(n, m_trail.get_num_scopes()); // allow sat_smt_solver to take over for another solver.       
 
         m_preprocess.pop(n);
         m_preprocess_state.pop(n);
@@ -357,7 +351,7 @@ public:
         m_solver.updt_params(m_params);
         m_solver.set_incremental(true);
         m_preprocess.updt_params(m_params);
-        if (sp.euf())
+        if (sp.smt())
             ensure_euf();
     }
     
@@ -537,7 +531,7 @@ public:
 
     void convert_internalized() {
         m_solver.pop_to_base_level();
-        if (!is_internalized() && m_preprocess.qhead() > 0) 
+        if (!is_internalized() && m_preprocess_state.qhead() > 0) 
             internalize_formulas();        
         if (!is_internalized() || m_internalized_converted) 
             return;
@@ -623,15 +617,19 @@ private:
         if (is_internalized())
             return l_true;
 
-        unsigned qhead = m_preprocess.qhead();
+        unsigned qhead = m_preprocess_state.qhead();
         m_trail.push(restore_vector(m_assumptions));
         m_trail.push(restore_vector(m_fmls));
         m_trail.push(value_trail(m_mc_size));
+        TRACE("sat", tout << "qhead " << qhead << "\n");
 
         m_internalized_converted = false;
 
         m_preprocess_state.replay(qhead);         
         m_preprocess.reduce();
+        if (!m.inc())
+            return l_undef;
+        m_preprocess_state.advance_qhead();
         m_preprocess_state.append(*m_mc);
         m_solver.pop_to_base_level();
         m_aux_fmls.reset();
@@ -695,7 +693,7 @@ private:
         mdl = nullptr;
         if (!m_solver.model_is_current()) 
             return;
-        if (m_fmls.size() > m_preprocess.qhead()) 
+        if (m_fmls.size() > m_preprocess_state.qhead()) 
             return;
         TRACE("sat", m_solver.display_model(tout););
         CTRACE("sat", m_sat_mc, m_sat_mc->display(tout););
diff --git a/src/sat/smt/q_mbi.cpp b/src/sat/smt/q_mbi.cpp
index 2c9b87c13..6f2db37e1 100644
--- a/src/sat/smt/q_mbi.cpp
+++ b/src/sat/smt/q_mbi.cpp
@@ -629,7 +629,7 @@ namespace q {
 
     void mbqi::init_solver() {
         if (!m_solver)
-            m_solver = mk_smt2_solver(m, m_no_drat_params);
+            m_solver = mk_smt2_solver(m, m_no_drat_params, symbol::null);
     }
 
     void mbqi::init_search() {
diff --git a/src/sat/tactic/goal2sat.cpp b/src/sat/tactic/goal2sat.cpp
index 0f23527dd..865c5f15d 100644
--- a/src/sat/tactic/goal2sat.cpp
+++ b/src/sat/tactic/goal2sat.cpp
@@ -99,7 +99,7 @@ struct goal2sat::imp : public sat::sat_internalizer {
         sat_params sp(p);
         m_ite_extra  = p.get_bool("ite_extra", true);
         m_max_memory = megabytes_to_bytes(p.get_uint("max_memory", UINT_MAX));
-        m_euf = sp.euf();
+        m_euf = sp.euf() || sp.smt();
     }
 
     void throw_op_not_handled(std::string const& s) {
diff --git a/src/solver/solver.h b/src/solver/solver.h
index 4ffdd5092..957cb7c8e 100644
--- a/src/solver/solver.h
+++ b/src/solver/solver.h
@@ -35,7 +35,7 @@ public:
 
 solver_factory * mk_smt_strategic_solver_factory(symbol const & logic = symbol::null);
 
-solver* mk_smt2_solver(ast_manager& m, params_ref const& p);
+solver* mk_smt2_solver(ast_manager& m, params_ref const& p, symbol const& logic = symbol::null);
 
 /**
    \brief Abstract interface for making solvers available in the Z3
diff --git a/src/tactic/arith/card2bv_tactic.h b/src/tactic/arith/card2bv_tactic.h
index 95282d93c..63cb021d7 100644
--- a/src/tactic/arith/card2bv_tactic.h
+++ b/src/tactic/arith/card2bv_tactic.h
@@ -30,7 +30,7 @@ public:
 };
 
 inline tactic* mk_card2bv_tactic(ast_manager& m, params_ref const& p = params_ref()) {
-    return alloc(dependent_expr_state_tactic, m, p, alloc(card2bv_tactic_factory), "card2bv");
+    return alloc(dependent_expr_state_tactic, m, p, alloc(card2bv_tactic_factory));
 }
 
 /*
diff --git a/src/tactic/bv/bv_slice_tactic.cpp b/src/tactic/bv/bv_slice_tactic.cpp
index 040068e39..17d69c7b1 100644
--- a/src/tactic/bv/bv_slice_tactic.cpp
+++ b/src/tactic/bv/bv_slice_tactic.cpp
@@ -29,5 +29,5 @@ public:
 };
 
 tactic* mk_bv_slice_tactic(ast_manager& m, params_ref const& p) {
-    return alloc(dependent_expr_state_tactic, m, p, alloc(bv_slice_factory), "bv-slice");
+    return alloc(dependent_expr_state_tactic, m, p, alloc(bv_slice_factory));
 }
diff --git a/src/tactic/bv/max_bv_sharing_tactic.h b/src/tactic/bv/max_bv_sharing_tactic.h
index ebd050aa5..3521b4a04 100644
--- a/src/tactic/bv/max_bv_sharing_tactic.h
+++ b/src/tactic/bv/max_bv_sharing_tactic.h
@@ -32,7 +32,7 @@ public:
 };
 
 inline tactic* mk_max_bv_sharing_tactic(ast_manager& m, params_ref const& p = params_ref()) {
-    return alloc(dependent_expr_state_tactic, m, p, alloc(max_bv_sharing_tactic_factory), "max-bv-sharing");
+    return alloc(dependent_expr_state_tactic, m, p, alloc(max_bv_sharing_tactic_factory));
 }
 
 /*
diff --git a/src/tactic/core/elim_uncnstr2_tactic.h b/src/tactic/core/elim_uncnstr2_tactic.h
index d9f6196f2..e7226a8f0 100644
--- a/src/tactic/core/elim_uncnstr2_tactic.h
+++ b/src/tactic/core/elim_uncnstr2_tactic.h
@@ -29,7 +29,7 @@ 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-uncnstr2");
+    return alloc(dependent_expr_state_tactic, m, p, alloc(elim_uncnstr2_tactic_factory));
 }
 
 
diff --git a/src/tactic/core/eliminate_predicates_tactic.h b/src/tactic/core/eliminate_predicates_tactic.h
index 3daffb1f3..de2291260 100644
--- a/src/tactic/core/eliminate_predicates_tactic.h
+++ b/src/tactic/core/eliminate_predicates_tactic.h
@@ -17,9 +17,9 @@ Author:
 #pragma once
 
 #include "util/params.h"
+#include "ast/simplifiers/eliminate_predicates.h"
 #include "tactic/tactic.h"
 #include "tactic/dependent_expr_state_tactic.h"
-#include "ast/simplifiers/eliminate_predicates.h"
 
 
 class eliminate_predicates_tactic_factory : public dependent_expr_simplifier_factory {
@@ -30,7 +30,7 @@ public:
 };
 
 inline tactic * mk_eliminate_predicates_tactic(ast_manager& m, params_ref const& p = params_ref()) {
-    return alloc(dependent_expr_state_tactic, m, p, alloc(eliminate_predicates_tactic_factory), "elim-predicates");
+    return alloc(dependent_expr_state_tactic, m, p, alloc(eliminate_predicates_tactic_factory));
 }
 
 /*
diff --git a/src/tactic/core/euf_completion_tactic.cpp b/src/tactic/core/euf_completion_tactic.cpp
index bdd940f17..d229df62f 100644
--- a/src/tactic/core/euf_completion_tactic.cpp
+++ b/src/tactic/core/euf_completion_tactic.cpp
@@ -28,5 +28,5 @@ public:
 };
 
 tactic * mk_euf_completion_tactic(ast_manager& m, params_ref const& p) {
-    return alloc(dependent_expr_state_tactic, m, p, alloc(euf_completion_tactic_factory), "euf-completion");
+    return alloc(dependent_expr_state_tactic, m, p, alloc(euf_completion_tactic_factory));
 }
diff --git a/src/tactic/core/propagate_values2_tactic.h b/src/tactic/core/propagate_values2_tactic.h
index 58e263e80..834e8bebd 100644
--- a/src/tactic/core/propagate_values2_tactic.h
+++ b/src/tactic/core/propagate_values2_tactic.h
@@ -31,7 +31,7 @@ public:
 };
 
 inline tactic * mk_propagate_values2_tactic(ast_manager & m, params_ref const & p = params_ref()) {
-    return alloc(dependent_expr_state_tactic, m, p, alloc(propagate_values2_tactic_factory), "propagate-values2");
+    return alloc(dependent_expr_state_tactic, m, p, alloc(propagate_values2_tactic_factory));
 }
 
 
diff --git a/src/tactic/core/solve_eqs_tactic.h b/src/tactic/core/solve_eqs_tactic.h
index 5d6da2e9a..76a738660 100644
--- a/src/tactic/core/solve_eqs_tactic.h
+++ b/src/tactic/core/solve_eqs_tactic.h
@@ -30,7 +30,7 @@ public:
 };
 
 inline tactic * mk_solve_eqs_tactic(ast_manager& m, params_ref const& p = params_ref()) {
-    return alloc(dependent_expr_state_tactic, m, p, alloc(solve_eqs_tactic_factory), "solve-eqs");
+    return alloc(dependent_expr_state_tactic, m, p, alloc(solve_eqs_tactic_factory));
 }
 
 /*
diff --git a/src/tactic/dependent_expr_state_tactic.h b/src/tactic/dependent_expr_state_tactic.h
index f16bb0ff3..dda114c24 100644
--- a/src/tactic/dependent_expr_state_tactic.h
+++ b/src/tactic/dependent_expr_state_tactic.h
@@ -22,7 +22,6 @@ Author:
 class dependent_expr_state_tactic : public tactic, public dependent_expr_state {
     ast_manager&    m;
     params_ref      m_params;
-    std::string     m_name;
     trail_stack     m_trail;
     goal_ref        m_goal;
     dependent_expr  m_dep;
@@ -42,10 +41,9 @@ class dependent_expr_state_tactic : public tactic, public dependent_expr_state {
 
 public:
 
-    dependent_expr_state_tactic(ast_manager& m, params_ref const& p, dependent_expr_simplifier_factory* f, char const* name):
+    dependent_expr_state_tactic(ast_manager& m, params_ref const& p, dependent_expr_simplifier_factory* f):
         m(m),
         m_params(p),
-        m_name(name),
         m_factory(f),
         m_simp(nullptr),
         m_dep(m, m.mk_true(), nullptr)
@@ -79,7 +77,7 @@ public:
         return *m_model_trail;
     }
         
-    char const* name() const override { return m_name.c_str(); }
+    char const* name() const override { return m_simp?m_simp->name():"null"; }
 
     void updt_params(params_ref const & p) override {
         m_params.append(p);
@@ -93,7 +91,7 @@ public:
     }
 
     tactic * translate(ast_manager & m) override {
-        return alloc(dependent_expr_state_tactic, m, m_params, m_factory.get(), name());
+        return alloc(dependent_expr_state_tactic, m, m_params, m_factory.get());
     }
 
     void operator()(goal_ref const & in, 
@@ -105,10 +103,12 @@ public:
         try {
             if (!in->proofs_enabled())
                 m_simp->reduce();
+            if (m.inc())
+                advance_qhead();
         }
         catch (rewriter_exception& ex) {
             throw tactic_exception(ex.msg());
-        }
+        }       
         m_goal->elim_true();
         m_goal->elim_redundancies();
         m_goal->inc_depth();
diff --git a/src/tactic/portfolio/smt_strategic_solver.cpp b/src/tactic/portfolio/smt_strategic_solver.cpp
index 1a9fc0f56..8acfbe40d 100644
--- a/src/tactic/portfolio/smt_strategic_solver.cpp
+++ b/src/tactic/portfolio/smt_strategic_solver.cpp
@@ -47,6 +47,7 @@ Notes:
 #include "solver/parallel_params.hpp"
 #include "params/tactic_params.hpp"
 #include "parsers/smt2/smt2parser.h"
+#include "sat/sat_params.hpp"
 
 
 
@@ -114,6 +115,15 @@ static solver* mk_special_solver_for_logic(ast_manager & m, params_ref const & p
     return nullptr;
 }
 
+solver* mk_smt2_solver(ast_manager& m, params_ref const& p, symbol const& logic) {
+    sat_params sp(p);
+    if (sp.smt())
+        return mk_sat_smt_solver(m, p);
+    if (sp.euf())
+        return mk_inc_sat_solver(m, p);
+    return mk_smt_solver(m, p, logic);
+}
+
 static solver* mk_solver_for_logic(ast_manager & m, params_ref const & p, symbol const& logic) {
     bv_rewriter rw(m);
     solver* s = mk_special_solver_for_logic(m, p, logic);
@@ -123,7 +133,7 @@ static solver* mk_solver_for_logic(ast_manager & m, params_ref const & p, symbol
     if (!s && tp.default_tactic() == "sat")
         s = mk_inc_sat_solver(m, p);
     if (!s) 
-        s = mk_smt_solver(m, p, logic);
+        s = mk_smt2_solver(m, p, logic);
     return s;
 }
 
@@ -170,6 +180,4 @@ solver_factory * mk_smt_strategic_solver_factory(symbol const & logic) {
     return alloc(smt_strategic_solver_factory, logic);
 }
 
-solver* mk_smt2_solver(ast_manager& m, params_ref const& p) {
-    return mk_inc_sat_solver(m, p);
-}
+