diff --git a/src/ast/rewriter/expr_replacer.h b/src/ast/rewriter/expr_replacer.h
index c1bfabd12..96418f00b 100644
--- a/src/ast/rewriter/expr_replacer.h
+++ b/src/ast/rewriter/expr_replacer.h
@@ -39,6 +39,7 @@ public:
     void operator()(expr * t, expr_ref & result);
     void operator()(expr_ref & t) { expr_ref s(t, m()); (*this)(s, t); }
     void operator()(expr_ref_vector& v) { expr_ref t(m());  for (unsigned i = 0; i < v.size(); ++i) (*this)(v.get(i), t), v[i] = t; }
+    std::pair<expr_ref, expr_dependency_ref> replace_with_dep(expr* t) { expr_ref r(m()); expr_dependency_ref d(m()); (*this)(t, r, d); return { r, d }; }
 
     virtual unsigned get_num_steps() const { return 0; }
     virtual void reset() = 0;
diff --git a/src/ast/simplifiers/bv_slice.cpp b/src/ast/simplifiers/bv_slice.cpp
index f39fa932e..75e0a890c 100644
--- a/src/ast/simplifiers/bv_slice.cpp
+++ b/src/ast/simplifiers/bv_slice.cpp
@@ -109,12 +109,12 @@ namespace bv {
         };
         if (lo > 0 && !b.contains(lo)) {
             b.insert(lo); 
-            if (m_num_scopes > 0)
+            if (num_scopes() > 0)
                 m_trail.push(remove_set(b, lo));
         }
         if (hi + 1 < sz && !b.contains(hi + 1)) {
             b.insert(hi + 1); 
-            if (m_num_scopes > 0)
+            if (num_scopes() > 0)
                 m_trail.push(remove_set(b, hi+ 1));
         }
     }
diff --git a/src/ast/simplifiers/dependent_expr_state.h b/src/ast/simplifiers/dependent_expr_state.h
index 32ad59681..803c58510 100644
--- a/src/ast/simplifiers/dependent_expr_state.h
+++ b/src/ast/simplifiers/dependent_expr_state.h
@@ -34,6 +34,7 @@ Author:
 #include "util/params.h"
 #include "ast/converters/model_converter.h"
 #include "ast/simplifiers/dependent_expr.h"
+#include "ast/simplifiers/model_reconstruction_trail.h"
 
 
 /**
@@ -46,6 +47,12 @@ public:
     virtual dependent_expr const& operator[](unsigned i) = 0;
     virtual void update(unsigned i, dependent_expr const& j) = 0;
     virtual bool inconsistent() = 0;
+
+    trail_stack    m_trail;
+    void push() { m_trail.push_scope(); }
+    void pop(unsigned n) { m_trail.pop_scope(n); }
+
+    virtual model_reconstruction_trail* model_trail() { return nullptr; }
 };
 
 /**
@@ -55,20 +62,21 @@ class dependent_expr_simplifier {
 protected:
     ast_manager&          m;
     dependent_expr_state& m_fmls;
-    unsigned       m_qhead = 0;          // pointer into last processed formula in m_fmls
-    unsigned       m_num_scopes = 0;
-    trail_stack    m_trail;    
-    void advance_qhead(unsigned sz) { if (m_num_scopes > 0) m_trail.push(value_trail(m_qhead)); m_qhead = sz; }
+    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(unsigned sz) { if (num_scopes() > 0) m_trail.push(value_trail(m_qhead)); m_qhead = sz; }
 public:
-    dependent_expr_simplifier(ast_manager& m, dependent_expr_state& s) : m(m), m_fmls(s) {}
+    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 void push() { m_num_scopes++; m_trail.push_scope(); }
-    virtual void pop(unsigned n) { m_num_scopes -= n; m_trail.pop_scope(n); }
+    virtual void push() { }
+    virtual void pop(unsigned n) { }
     virtual void reduce() = 0;
     virtual void collect_statistics(statistics& st) const {}
     virtual void reset_statistics() {}
     virtual void updt_params(params_ref const& p) {}
-    virtual model_converter_ref get_model_converter() { return model_converter_ref(); }
 };
 
 /**
diff --git a/src/ast/simplifiers/euf_completion.cpp b/src/ast/simplifiers/euf_completion.cpp
index e5b328d7f..e1360fa0b 100644
--- a/src/ast/simplifiers/euf_completion.cpp
+++ b/src/ast/simplifiers/euf_completion.cpp
@@ -213,7 +213,7 @@ namespace euf {
                 old_value = nullptr;
             }
         };
-        if (m_num_scopes > 0)
+        if (num_scopes() > 0)
             m_trail.push(vtrail(m_canonical, n->get_id()));
         m_canonical.setx(n->get_id(), e);
         m_epochs.setx(n->get_id(), m_epoch, 0);
diff --git a/src/ast/simplifiers/model_reconstruction_trail.cpp b/src/ast/simplifiers/model_reconstruction_trail.cpp
index 077443e7e..a8e75bfa3 100644
--- a/src/ast/simplifiers/model_reconstruction_trail.cpp
+++ b/src/ast/simplifiers/model_reconstruction_trail.cpp
@@ -21,11 +21,12 @@ void model_reconstruction_trail::replay(dependent_expr const& d, vector<dependen
     // accumulate a set of dependent exprs, updating m_trail to exclude loose 
     // substitutions that use variables from the dependent expressions.
     ast_mark free_vars;
-    
+    scoped_ptr<expr_replacer> rp = mk_default_expr_replacer(m, false);
     add_vars(d, free_vars);
 
     added.push_back(d);
 
+
     for (auto& t : m_trail) {
         if (!t->m_active)
             continue;
@@ -45,13 +46,12 @@ void model_reconstruction_trail::replay(dependent_expr const& d, vector<dependen
             continue;
         }
         
+        rp->set_substitution(t->m_subst.get());
         // rigid entries:
         // apply substitution to added in case of rigid model convertions
         for (auto& d : added) {
             auto [f, dep1] = d();
-            expr_ref g(m);
-            expr_dependency_ref dep2(m);
-            (*t->m_replace)(f, g, dep2);
+            auto [g, dep2] = rp->replace_with_dep(f);
             d = dependent_expr(m, g, m.mk_join(dep1, dep2));
         }    
     }
@@ -69,9 +69,9 @@ model_converter_ref model_reconstruction_trail::get_model_converter() {
     // substituted variables by their terms.
     //
 
-    scoped_ptr<expr_replacer> rp = mk_default_expr_replacer(m, true);
-    scoped_ptr<expr_substitution> subst = alloc(expr_substitution, m, true, false);
-    rp->set_substitution(subst.get());
+    scoped_ptr<expr_replacer> rp = mk_default_expr_replacer(m, false);
+    expr_substitution subst(m, true, false);
+    rp->set_substitution(&subst);
     generic_model_converter_ref mc = alloc(generic_model_converter, m, "dependent-expr-model");
     bool first = true;
     for (unsigned i = m_trail.size(); i-- > 0; ) {
@@ -83,19 +83,17 @@ model_converter_ref model_reconstruction_trail::get_model_converter() {
             first = false;
             for (auto const& [v, def] : t->m_subst->sub()) {
                 expr_dependency* dep = t->m_subst->dep(v);
-                subst->insert(v, def, dep);
+                subst.insert(v, def, dep);
                 mc->add(v, def);
             }
             continue;
         }
-        expr_dependency_ref new_dep(m);
-        expr_ref new_def(m);
 
         for (auto const& [v, def] : t->m_subst->sub()) {
-            rp->operator()(def, new_def, new_dep);
+            auto [new_def, new_dep] = rp->replace_with_dep(def);
             expr_dependency* dep = t->m_subst->dep(v);
             new_dep = m.mk_join(dep, new_dep);
-            subst->insert(v, new_def, new_dep);
+            subst.insert(v, new_def, new_dep);
             mc->add(v, new_def);
         }
 
diff --git a/src/ast/simplifiers/model_reconstruction_trail.h b/src/ast/simplifiers/model_reconstruction_trail.h
index 4aa8a54fd..c9b42bc92 100644
--- a/src/ast/simplifiers/model_reconstruction_trail.h
+++ b/src/ast/simplifiers/model_reconstruction_trail.h
@@ -33,13 +33,12 @@ Author:
 class model_reconstruction_trail {
 
     struct entry {
-        scoped_ptr<expr_replacer>     m_replace;
         scoped_ptr<expr_substitution> m_subst;
         vector<dependent_expr>        m_removed;
         bool                          m_active = true;
 
-        entry(expr_replacer* r, expr_substitution* s, vector<dependent_expr> const& rem) :
-            m_replace(r), m_subst(s), m_removed(rem) {}
+        entry(expr_substitution* s, vector<dependent_expr> const& rem) :
+            m_subst(s), m_removed(rem) {}
 
         bool is_loose() const { return !m_removed.empty(); }
 
@@ -64,7 +63,8 @@ class model_reconstruction_trail {
 
     bool intersects(ast_mark const& free_vars, dependent_expr const& d) {
         expr_ref term(d.fml(), d.get_manager());
-        return any_of(subterms::all(term), [&](expr* t) { return free_vars.is_marked(t); });
+        auto iter = subterms::all(term);
+        return any_of(iter, [&](expr* t) { return free_vars.is_marked(t); });
     }
 
     bool intersects(ast_mark const& free_vars, vector<dependent_expr> const& added) {
@@ -77,10 +77,10 @@ public:
         m(m), m_trail_stack(tr) {}
 
     /**
-    * add a new substitution to the stack
+    * add a new substitution to the trail
     */
-    void push(expr_replacer* r, vector<dependent_expr> const& removed) {
-        m_trail.push_back(alloc(entry, r, nullptr, removed));
+    void push(expr_substitution* s, vector<dependent_expr> const& removed) {
+        m_trail.push_back(alloc(entry, s, removed));
         m_trail_stack.push(push_back_vector(m_trail));
     }
 
diff --git a/src/ast/simplifiers/solve_eqs.cpp b/src/ast/simplifiers/solve_eqs.cpp
index e4361ad97..b5b500a96 100644
--- a/src/ast/simplifiers/solve_eqs.cpp
+++ b/src/ast/simplifiers/solve_eqs.cpp
@@ -60,7 +60,7 @@ namespace euf {
         m_id2level.reset();
         m_id2level.resize(m_id2var.size(), UINT_MAX);
         m_subst_ids.reset();
-        m_subst = alloc(expr_substitution, m, true, false);
+        m_subst = alloc(expr_substitution, m, true, false);        
 
         auto is_explored = [&](unsigned id) {
             return m_id2level[id] != UINT_MAX;
@@ -105,30 +105,22 @@ namespace euf {
         }
     }
 
-    void solve_eqs::add_subst(dependent_eq const& eq) {
-        SASSERT(can_be_var(eq.var));
-        m_subst->insert(eq.var, eq.term, nullptr, eq.dep);
-        ++m_stats.m_num_elim_vars;
-    }
-
     void solve_eqs::normalize() {
         scoped_ptr<expr_replacer> rp = mk_default_expr_replacer(m, true);
-        m_subst->reset();
         rp->set_substitution(m_subst.get());
 
         std::sort(m_subst_ids.begin(), m_subst_ids.end(), [&](unsigned u, unsigned v) { return m_id2level[u] > m_id2level[v]; });
 
-        expr_dependency_ref new_dep(m);
-        expr_ref new_def(m);
-
         for (unsigned id : m_subst_ids) {
             if (!m.inc())
                 break;
             auto const& [v, def, dep] = m_next[id][0];
-            rp->operator()(def, new_def, new_dep);
+            auto [new_def, new_dep] = rp->replace_with_dep(def);
             m_stats.m_num_steps += rp->get_num_steps() + 1;
+            ++m_stats.m_num_elim_vars;
             new_dep = m.mk_join(dep, new_dep);
-            m_subst->insert(v, new_def, nullptr, new_dep);
+            m_subst->insert(v, new_def, new_dep);
+            SASSERT(can_be_var(v));
             // we updated the substitution, but we don't need to reset rp
             // because all cached values there do not depend on v.
         }
@@ -147,11 +139,10 @@ namespace euf {
             return;
         scoped_ptr<expr_replacer> rp = mk_default_expr_replacer(m, true);
         rp->set_substitution(m_subst.get());
-        expr_ref new_f(m);
-        expr_dependency_ref new_dep(m);
+
         for (unsigned i = m_qhead; i < m_fmls.size() && !m_fmls.inconsistent(); ++i) {
             auto [f, d] = m_fmls[i]();
-            rp->operator()(f, new_f, new_dep);
+            auto [new_f, new_dep] = rp->replace_with_dep(f);
             if (new_f == f)
                 continue;
             new_dep = m.mk_join(d, new_dep);
@@ -164,13 +155,27 @@ namespace euf {
         for (extract_eq* ex : m_extract_plugins)
             ex->pre_process(m_fmls);
 
-        // TODO add a loop.
-        dep_eq_vector eqs;
-        get_eqs(eqs);
-        extract_dep_graph(eqs);
-        extract_subst();
-        apply_subst();
+        unsigned count = 0;
+        do {
+            m_subst_ids.reset();
+            if (!m.inc())
+                return;
+            dep_eq_vector eqs;
+            get_eqs(eqs);
+            extract_dep_graph(eqs);
+            extract_subst();
+            apply_subst();
+            ++count;
+        } 
+        while (!m_subst_ids.empty() && count < 20);
+
         advance_qhead(m_fmls.size());
+        save_subst();
+    }
+
+    void solve_eqs::save_subst() {
+        if (!m_subst->empty())   
+            m_fmls.model_trail()->push(m_subst.detach(), {});        
     }
 
     void solve_eqs::filter_unsafe_vars() {
@@ -181,16 +186,7 @@ namespace euf {
                 m_unsafe_vars.mark(term);
     }
 
-    typedef generic_model_converter gmc;
 
-    model_converter_ref solve_eqs::get_model_converter() {
-        model_converter_ref mc = alloc(gmc, m, "solve-eqs");
-        for (unsigned id : m_subst_ids) {
-            auto* v = m_id2var[id];
-            static_cast<gmc*>(mc.get())->add(v, m_subst->find(v));
-        }
-        return mc;
-    }
 
     solve_eqs::solve_eqs(ast_manager& m, dependent_expr_state& fmls) : 
         dependent_expr_simplifier(m, fmls), m_rewriter(m) {
diff --git a/src/ast/simplifiers/solve_eqs.h b/src/ast/simplifiers/solve_eqs.h
index 49cd90ca2..db7a1323b 100644
--- a/src/ast/simplifiers/solve_eqs.h
+++ b/src/ast/simplifiers/solve_eqs.h
@@ -67,6 +67,7 @@ namespace euf {
         void extract_dep_graph(dep_eq_vector& eqs);
         void normalize();
         void apply_subst();
+        void save_subst();
 
     public:
 
@@ -78,7 +79,5 @@ namespace euf {
 
         void updt_params(params_ref const& p) override;
         void collect_statistics(statistics& st) const override;
-
-        model_converter_ref get_model_converter() override;
     };
 }
diff --git a/src/tactic/dependent_expr_state_tactic.h b/src/tactic/dependent_expr_state_tactic.h
index ae3635c77..719a29eea 100644
--- a/src/tactic/dependent_expr_state_tactic.h
+++ b/src/tactic/dependent_expr_state_tactic.h
@@ -24,12 +24,16 @@ class dependent_expr_state_tactic : public tactic, public dependent_expr_state {
     std::string     m_name;
     ref<dependent_expr_simplifier_factory>  m_factory;
     scoped_ptr<dependent_expr_simplifier>   m_simp;
+    trail_stack                             m_trail;
+    scoped_ptr<model_reconstruction_trail>  m_model_trail;
     goal_ref        m_goal;
     dependent_expr  m_dep;
 
     void init() {
         if (!m_simp)
             m_simp = m_factory->mk(m, m_params, *this);
+        if (!m_model_trail)
+            m_model_trail = alloc(model_reconstruction_trail, m, m_trail);
     }
 
 public:
@@ -60,6 +64,10 @@ public:
     bool inconsistent() override {
         return m_goal->inconsistent();
     }
+
+    model_reconstruction_trail* model_trail() override {
+        return m_model_trail.get();
+    }
         
     char const* name() const override { return m_name.c_str(); }
 
@@ -83,7 +91,7 @@ public:
         m_simp->reduce();
         m_goal->inc_depth();
         if (in->models_enabled())
-            in->set(m_simp->get_model_converter().get());
+            in->set(m_model_trail->get_model_converter().get());
         result.push_back(in.get());        
     }
 
diff --git a/src/util/util.h b/src/util/util.h
index c3f06d8d3..925e20186 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -367,7 +367,6 @@ bool any_of(S& set, T& p) {
             return true;
     return false;
 }
-// #define any_of(S, p) { for (auto const& s : S) if (p(s)) return true; return false; }
 
 /**
    \brief Iterator for the [0..sz[0]) X [0..sz[1]) X ... X [0..sz[n-1]).