diff --git a/src/api/c++/z3++.h b/src/api/c++/z3++.h
index 06c12741c..a2937cb8e 100644
--- a/src/api/c++/z3++.h
+++ b/src/api/c++/z3++.h
@@ -1883,7 +1883,7 @@ namespace z3 {
         bool is_uint(unsigned i) const { Z3_bool r = Z3_stats_is_uint(ctx(), m_stats, i); check_error(); return r != 0; }
         bool is_double(unsigned i) const { Z3_bool r = Z3_stats_is_double(ctx(), m_stats, i); check_error(); return r != 0; }
         unsigned uint_value(unsigned i) const { unsigned r = Z3_stats_get_uint_value(ctx(), m_stats, i); check_error(); return r; }
-        double double_value(unsigned i) const { double r = Z3_stats_get_double_value(ctx(), m_stats, i); check_error(); return r; }
+        double double_value(unsigned i) const { double r = Z3_stats_get_double_value(ctx(), m_stats, i); check_error(); return r; }        
         friend std::ostream & operator<<(std::ostream & out, stats const & s);
     };
     inline std::ostream & operator<<(std::ostream & out, stats const & s) { out << Z3_stats_to_string(s.ctx(), s); return out; }
diff --git a/src/muz/base/dl_rule.cpp b/src/muz/base/dl_rule.cpp
index 4f832c4c9..c188426f0 100644
--- a/src/muz/base/dl_rule.cpp
+++ b/src/muz/base/dl_rule.cpp
@@ -41,7 +41,7 @@ Revision History:
 #include "ast/rewriter/expr_replacer.h"
 #include "ast/rewriter/bool_rewriter.h"
 #include "ast/rewriter/expr_safe_replace.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/scoped_proof.h"
 #include "ast/datatype_decl_plugin.h"
 #include "ast/ast_util.h"
@@ -326,8 +326,8 @@ namespace datalog {
         rules.set_output_predicate(qpred);
 
         if (m_ctx.get_model_converter()) {
-            filter_model_converter* mc = alloc(filter_model_converter, m);
-            mc->insert(qpred);
+            generic_model_converter* mc = alloc(generic_model_converter, m);
+            mc->hide(qpred);
             m_ctx.add_model_converter(mc);
         }
 
diff --git a/src/muz/fp/horn_tactic.cpp b/src/muz/fp/horn_tactic.cpp
index 5db57a12c..ded33bb0d 100644
--- a/src/muz/fp/horn_tactic.cpp
+++ b/src/muz/fp/horn_tactic.cpp
@@ -25,7 +25,7 @@ Revision History:
 #include "ast/rewriter/expr_replacer.h"
 #include "muz/base/dl_rule_transformer.h"
 #include "muz/transforms/dl_mk_slice.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "muz/transforms/dl_transforms.h"
 #include "muz/base/fixedpoint_params.hpp"
 #include "ast/ast_util.h"
@@ -229,8 +229,8 @@ class horn_tactic : public tactic {
                 }
                 queries.reset();
                 queries.push_back(q);
-                filter_model_converter* mc1 = alloc(filter_model_converter, m);
-                mc1->insert(to_app(q)->get_decl());
+                generic_model_converter* mc1 = alloc(generic_model_converter, m);
+                mc1->hide(q);
                 mc = mc1;
             }
             SASSERT(queries.size() == 1);
diff --git a/src/muz/spacer/spacer_itp_solver.h b/src/muz/spacer/spacer_itp_solver.h
index ab3b94894..84469f490 100644
--- a/src/muz/spacer/spacer_itp_solver.h
+++ b/src/muz/spacer/spacer_itp_solver.h
@@ -112,10 +112,10 @@ public:
     {m_solver.collect_param_descrs(r);}
     virtual void set_produce_models(bool f)
     {m_solver.set_produce_models(f);}
-    virtual void assert_expr(expr *t)
+    virtual void assert_expr_core(expr *t)
     {m_solver.assert_expr(t);}
 
-    virtual void assert_expr(expr *t, expr *a)
+    virtual void assert_expr_core(expr *t, expr *a)
     {NOT_IMPLEMENTED_YET();}
     virtual void assert_lemma(expr* e) { NOT_IMPLEMENTED_YET(); }
     virtual expr_ref lookahead(const expr_ref_vector &,const expr_ref_vector &) { return expr_ref(m.mk_true(), m); }
diff --git a/src/muz/spacer/spacer_virtual_solver.cpp b/src/muz/spacer/spacer_virtual_solver.cpp
index 938e8cb94..0c3adbbbd 100644
--- a/src/muz/spacer/spacer_virtual_solver.cpp
+++ b/src/muz/spacer/spacer_virtual_solver.cpp
@@ -50,7 +50,7 @@ virtual_solver::virtual_solver(virtual_solver_factory &factory,
     // -- change m_context, but will add m_pred to
     // -- the private field solver_na2as::m_assumptions
     if (m_virtual)
-    { solver_na2as::assert_expr(m.mk_true(), m_pred); }
+    { solver_na2as::assert_expr_core(m.mk_true(), m_pred); }
 }
 
 virtual_solver::~virtual_solver()
@@ -210,7 +210,7 @@ void virtual_solver::get_unsat_core(ptr_vector<expr> &r)
     }
 }
 
-void virtual_solver::assert_expr(expr *e)
+void virtual_solver::assert_expr_core(expr *e)
 {
     SASSERT(!m_pushed || get_scope_level() > 0);
     if (m.is_true(e)) { return; }
diff --git a/src/muz/spacer/spacer_virtual_solver.h b/src/muz/spacer/spacer_virtual_solver.h
index 3b256f297..946df95ad 100644
--- a/src/muz/spacer/spacer_virtual_solver.h
+++ b/src/muz/spacer/spacer_virtual_solver.h
@@ -78,7 +78,7 @@ public:
     }
 
     virtual void get_unsat_core(ptr_vector<expr> &r);
-    virtual void assert_expr(expr *e);
+    virtual void assert_expr_core(expr *e);
     virtual void collect_statistics(statistics &st) const {}
     virtual void get_model_core(model_ref &m) {m_context.get_model(m);}
     virtual proof* get_proof();
diff --git a/src/muz/transforms/dl_mk_bit_blast.cpp b/src/muz/transforms/dl_mk_bit_blast.cpp
index 924b12eda..7f3ae43f3 100644
--- a/src/muz/transforms/dl_mk_bit_blast.cpp
+++ b/src/muz/transforms/dl_mk_bit_blast.cpp
@@ -22,7 +22,7 @@ Revision History:
 #include "ast/rewriter/rewriter_def.h"
 #include "ast/ast_pp.h"
 #include "ast/rewriter/expr_safe_replace.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "muz/transforms/dl_mk_interp_tail_simplifier.h"
 #include "muz/base/fixedpoint_params.hpp"
 #include "ast/scoped_proof.h"
@@ -299,12 +299,12 @@ namespace datalog {
             }
             
             if (m_context.get_model_converter()) {               
-                filter_model_converter* fmc = alloc(filter_model_converter, m);
+                generic_model_converter* fmc = alloc(generic_model_converter, m);
                 bit_blast_model_converter* bvmc = alloc(bit_blast_model_converter, m);
                 func_decl_ref_vector const& old_funcs = m_rewriter.m_cfg.old_funcs();
                 func_decl_ref_vector const& new_funcs = m_rewriter.m_cfg.new_funcs();
                 for (unsigned i = 0; i < old_funcs.size(); ++i) {
-                    fmc->insert(new_funcs[i]);
+                    fmc->hide(new_funcs[i]);
                     bvmc->insert(old_funcs[i], new_funcs[i]);
                 }
                 m_context.add_model_converter(concat(bvmc, fmc));
diff --git a/src/opt/maxsmt.cpp b/src/opt/maxsmt.cpp
index 8df6c04a6..25616b00f 100644
--- a/src/opt/maxsmt.cpp
+++ b/src/opt/maxsmt.cpp
@@ -105,7 +105,7 @@ namespace opt {
 
     app* maxsmt_solver_base::mk_fresh_bool(char const* name) {
         app* result = m.mk_fresh_const(name, m.mk_bool_sort());
-        m_c.fm().insert(result->get_decl());
+        m_c.fm().hide(result);
         return result;
     }
 
diff --git a/src/opt/maxsmt.h b/src/opt/maxsmt.h
index 0541a9a88..636afcddd 100644
--- a/src/opt/maxsmt.h
+++ b/src/opt/maxsmt.h
@@ -22,7 +22,6 @@ Notes:
 #include "ast/ast.h"
 #include "util/params.h"
 #include "solver/solver.h"
-#include "tactic/filter_model_converter.h"
 #include "util/statistics.h"
 #include "smt/smt_context.h"
 #include "smt/smt_theory.h"
diff --git a/src/opt/opt_context.cpp b/src/opt/opt_context.cpp
index 045dcafd4..2ab6abd79 100644
--- a/src/opt/opt_context.cpp
+++ b/src/opt/opt_context.cpp
@@ -40,7 +40,7 @@ Notes:
 #include "ast/bv_decl_plugin.h"
 #include "ast/pb_decl_plugin.h"
 #include "ast/ast_smt_pp.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/ast_pp_util.h"
 #include "qe/qsat.h"
 
@@ -1021,7 +1021,7 @@ namespace opt {
     }
 
     void context::purify(app_ref& term) {
-        filter_model_converter_ref fm;
+        generic_model_converter_ref fm;
         if (m_arith.is_add(term)) {
             expr_ref_vector args(m);
             unsigned sz = term->get_num_args();
@@ -1058,13 +1058,13 @@ namespace opt {
             (m_arith.is_mul(e, e2, e1) && m_arith.is_numeral(e1) && is_uninterp_const(e2));
     }
 
-    app* context::purify(filter_model_converter_ref& fm, expr* term) {
+    app* context::purify(generic_model_converter_ref& fm, expr* term) {
        std::ostringstream out;
        out << mk_pp(term, m);
        app* q = m.mk_fresh_const(out.str().c_str(), m.get_sort(term));
-       if (!fm) fm = alloc(filter_model_converter, m);
+       if (!fm) fm = alloc(generic_model_converter, m);
        m_hard_constraints.push_back(m.mk_eq(q, term));
-       fm->insert(q->get_decl());                
+       fm->hide(q);
        return q;
     }
 
@@ -1075,7 +1075,7 @@ namespace opt {
        - filter "obj" from generated model.
      */
     void context::mk_atomic(expr_ref_vector& terms) {
-        filter_model_converter_ref fm;
+        generic_model_converter_ref fm;
         for (unsigned i = 0; i < terms.size(); ++i) {
             expr_ref p(terms[i].get(), m);
             app_ref q(m);
diff --git a/src/opt/opt_context.h b/src/opt/opt_context.h
index 4fec5d452..be0ef873c 100644
--- a/src/opt/opt_context.h
+++ b/src/opt/opt_context.h
@@ -45,7 +45,7 @@ namespace opt {
 
     class maxsat_context {
     public:        
-        virtual filter_model_converter& fm() = 0;   // converter that removes fresh names introduced by simplification.
+        virtual generic_model_converter& fm() = 0;   // converter that removes fresh names introduced by simplification.
         virtual bool sat_enabled() const = 0;       // is using th SAT solver core enabled?
         virtual solver& get_solver() = 0;           // retrieve solver object (SAT or SMT solver)
         virtual ast_manager& get_manager() const = 0;      
@@ -155,7 +155,7 @@ namespace opt {
         vector<objective>   m_objectives;
         model_ref           m_model;
         model_converter_ref          m_model_converter;
-        filter_model_converter       m_fm;
+        generic_model_converter       m_fm;
         obj_map<func_decl, unsigned> m_objective_fns;
         obj_map<func_decl, expr*>    m_objective_orig;
         func_decl_ref_vector         m_objective_refs;
@@ -219,7 +219,7 @@ namespace opt {
         virtual expr_ref mk_le(unsigned i, model_ref& model);
 
         virtual smt::context& smt_context() { return m_opt_solver->get_context(); }
-        virtual filter_model_converter& fm() { return m_fm; }
+        virtual generic_model_converter& fm() { return m_fm; }
         virtual bool sat_enabled() const { return 0 != m_sat_solver.get(); }
         virtual solver& get_solver();
         virtual ast_manager& get_manager() const { return this->m; }
@@ -253,7 +253,7 @@ namespace opt {
                        vector<rational>& weights, rational& offset, bool& neg, 
                        symbol& id, expr_ref& orig_term, unsigned& index);
         void  purify(app_ref& term);
-        app* purify(filter_model_converter_ref& fm, expr* e);
+        app* purify(generic_model_converter_ref& fm, expr* e);
         bool is_mul_const(expr* e);
         expr* mk_maximize(unsigned index, app* t);
         expr* mk_minimize(unsigned index, app* t);
diff --git a/src/opt/opt_solver.cpp b/src/opt/opt_solver.cpp
index 3eb435fd7..b14e99c48 100644
--- a/src/opt/opt_solver.cpp
+++ b/src/opt/opt_solver.cpp
@@ -37,7 +37,7 @@ Notes:
 namespace opt {
 
     opt_solver::opt_solver(ast_manager & mgr, params_ref const & p, 
-                           filter_model_converter& fm):
+                           generic_model_converter& fm):
         solver_na2as(mgr),
         m_params(p),
         m_context(mgr, m_params),
@@ -80,7 +80,7 @@ namespace opt {
         m_context.collect_statistics(st);
     }
     
-    void opt_solver::assert_expr(expr * t) {
+    void opt_solver::assert_expr_core(expr * t) {
         if (has_quantifiers(t)) {
             m_params.m_relevancy_lvl = 2;
         }
diff --git a/src/opt/opt_solver.h b/src/opt/opt_solver.h
index 61947e768..9d1eccb38 100644
--- a/src/opt/opt_solver.h
+++ b/src/opt/opt_solver.h
@@ -30,7 +30,7 @@ Notes:
 #include "smt/params/smt_params.h"
 #include "smt/smt_types.h"
 #include "smt/theory_opt.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 
 namespace opt {
 
@@ -70,7 +70,7 @@ namespace opt {
         smt_params          m_params;
         smt::kernel         m_context;
         ast_manager&        m;
-        filter_model_converter& m_fm;
+        generic_model_converter& m_fm;
         progress_callback * m_callback;
         symbol              m_logic;
         svector<smt::theory_var>  m_objective_vars;
@@ -84,14 +84,14 @@ namespace opt {
         bool                m_first;
         bool                m_was_unknown;
     public:
-        opt_solver(ast_manager & m, params_ref const & p, filter_model_converter& fm);
+        opt_solver(ast_manager & m, params_ref const & p, generic_model_converter& fm);
         virtual ~opt_solver();
 
         virtual solver* translate(ast_manager& m, params_ref const& p);
         virtual void updt_params(params_ref const& p);
         virtual void collect_param_descrs(param_descrs & r);
         virtual void collect_statistics(statistics & st) const;
-        virtual void assert_expr(expr * t);
+        virtual void assert_expr_core(expr * t);
         virtual void assert_lemma(expr* t) {}
         virtual void push_core();
         virtual void pop_core(unsigned n);
diff --git a/src/opt/sortmax.cpp b/src/opt/sortmax.cpp
index f832d5564..18c3edc76 100644
--- a/src/opt/sortmax.cpp
+++ b/src/opt/sortmax.cpp
@@ -24,7 +24,7 @@ Notes:
 #include "smt/smt_context.h"
 #include "opt/opt_context.h"
 #include "util/sorting_network.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 
 namespace opt {
 
@@ -35,7 +35,7 @@ namespace opt {
         psort_nw<sortmax> m_sort;
         expr_ref_vector   m_trail;
         func_decl_ref_vector m_fresh;
-        ref<filter_model_converter> m_filter;
+        ref<generic_model_converter> m_filter;
         sortmax(maxsat_context& c, weights_t& ws, expr_ref_vector const& soft): 
             maxsmt_solver_base(c, ws, soft), m_sort(*this), m_trail(m), m_fresh(m) {}
 
@@ -50,7 +50,7 @@ namespace opt {
             if (is_sat != l_true) {
                 return is_sat;
             }
-            m_filter = alloc(filter_model_converter, m);
+            m_filter = alloc(generic_model_converter, m);
             rational offset = m_lower;
             m_upper = offset;
             expr_ref_vector in(m);
@@ -142,7 +142,7 @@ namespace opt {
             expr_ref fr(m.mk_fresh_const(n, m.mk_bool_sort()), m);
             func_decl* f = to_app(fr)->get_decl();
             m_fresh.push_back(f);
-            m_filter->insert(f);
+            m_filter->hide(f);
             return trail(fr);
         }
         
diff --git a/src/qe/qe_tactic.cpp b/src/qe/qe_tactic.cpp
index 5d1a74813..e198542c1 100644
--- a/src/qe/qe_tactic.cpp
+++ b/src/qe/qe_tactic.cpp
@@ -17,7 +17,6 @@ Revision History:
 
 --*/
 #include "tactic/tactical.h"
-#include "tactic/filter_model_converter.h"
 #include "util/cooperate.h"
 #include "qe/qe.h"
 
diff --git a/src/qe/qsat.cpp b/src/qe/qsat.cpp
index 713ecfe77..56f2ff985 100644
--- a/src/qe/qsat.cpp
+++ b/src/qe/qsat.cpp
@@ -44,11 +44,11 @@ namespace qe {
         m(m),
         m_asms(m),
         m_trail(m),
-        m_fmc(alloc(filter_model_converter, m))
+        m_fmc(alloc(generic_model_converter, m))
     {
     }
 
-    filter_model_converter* pred_abs::fmc() { 
+    generic_model_converter* pred_abs::fmc() { 
         return m_fmc.get(); 
     }
 
@@ -282,7 +282,7 @@ namespace qe {
 
     app_ref pred_abs::fresh_bool(char const* name) {
         app_ref r(m.mk_fresh_const(name, m.mk_bool_sort()), m);
-        m_fmc->insert(r->get_decl());
+        m_fmc->hide(r);
         return r;
     }
 
@@ -747,9 +747,7 @@ namespace qe {
         }
 
         void filter_vars(app_ref_vector const& vars) {
-            for (unsigned i = 0; i < vars.size(); ++i) {
-                m_pred_abs.fmc()->insert(vars[i]->get_decl());
-            }
+            for (app* v : vars) m_pred_abs.fmc()->hide(v);
         }        
 
         void initialize_levels() {
diff --git a/src/qe/qsat.h b/src/qe/qsat.h
index 85a8181d6..dca7cc00b 100644
--- a/src/qe/qsat.h
+++ b/src/qe/qsat.h
@@ -22,7 +22,7 @@ Revision History:
 #define QE_QSAT_H__
 
 #include "tactic/tactic.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "qe/qe_mbp.h"
 
 namespace qe {
@@ -72,7 +72,7 @@ namespace qe {
         obj_map<expr, app*>     m_asm2pred;    // maintain map from assumptions to predicates
         obj_map<expr, expr*>    m_pred2asm;    // predicates |-> assumptions
         expr_ref_vector         m_trail;
-        filter_model_converter_ref m_fmc;
+        generic_model_converter_ref m_fmc;
         ptr_vector<expr>        todo;
         obj_map<expr, max_level>      m_elevel;
         obj_map<func_decl, max_level> m_flevel;
@@ -91,7 +91,7 @@ namespace qe {
     public:
         
         pred_abs(ast_manager& m);
-        filter_model_converter* fmc();
+        generic_model_converter* fmc();
         void reset();
         max_level compute_level(app* e);
         void push();
diff --git a/src/sat/sat_solver/inc_sat_solver.cpp b/src/sat/sat_solver/inc_sat_solver.cpp
index b5efe57da..37f8b5d16 100644
--- a/src/sat/sat_solver/inc_sat_solver.cpp
+++ b/src/sat/sat_solver/inc_sat_solver.cpp
@@ -31,7 +31,6 @@ Notes:
 #include "sat/tactic/goal2sat.h"
 #include "ast/ast_pp.h"
 #include "model/model_smt2_pp.h"
-#include "tactic/filter_model_converter.h"
 #include "tactic/bv/bit_blaster_model_converter.h"
 #include "ast/ast_translation.h"
 #include "ast/ast_util.h"
@@ -241,13 +240,13 @@ public:
     virtual unsigned get_scope_level() const {
         return m_num_scopes;
     }
-    virtual void assert_expr(expr * t, expr * a) {
+    virtual void assert_expr_core(expr * t, expr * a) {
         if (a) {
             m_asmsf.push_back(a);
-            assert_expr(m.mk_implies(a, t));
+            assert_expr_core(m.mk_implies(a, t));
         }
         else {
-            assert_expr(t);
+            assert_expr_core(t);
         }
     }
 
@@ -261,7 +260,7 @@ public:
     }
 
     virtual ast_manager& get_manager() const { return m; }
-    virtual void assert_expr(expr * t) {
+    virtual void assert_expr_core(expr * t) {
         m_internalized = false;
         TRACE("goal2sat", tout << mk_pp(t, m) << "\n";);
         m_fmls.push_back(t);
diff --git a/src/sat/tactic/goal2sat.cpp b/src/sat/tactic/goal2sat.cpp
index c70077dc5..f037a0e26 100644
--- a/src/sat/tactic/goal2sat.cpp
+++ b/src/sat/tactic/goal2sat.cpp
@@ -38,7 +38,7 @@ Notes:
 #include "model/model_evaluator.h"
 #include "model/model_v2_pp.h"
 #include "tactic/tactic.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include<sstream>
 
 struct goal2sat::imp {
@@ -883,7 +883,7 @@ struct sat2goal::imp {
     class sat_model_converter : public model_converter {
         sat::model_converter        m_mc;
         expr_ref_vector             m_var2expr;
-        filter_model_converter_ref  m_fmc; // filter for eliminating fresh variables introduced in the assertion-set --> sat conversion
+        generic_model_converter_ref  m_fmc; // filter for eliminating fresh variables introduced in the assertion-set --> sat conversion
         
         sat_model_converter(ast_manager & m):
             m_var2expr(m) {
@@ -892,7 +892,7 @@ struct sat2goal::imp {
     public:
         sat_model_converter(ast_manager & m, sat::solver const & s):m_var2expr(m) {
             m_mc.copy(s.get_model_converter());
-            m_fmc = alloc(filter_model_converter, m);
+            m_fmc = alloc(generic_model_converter, m);
         }
         
         ast_manager & m() { return m_var2expr.get_manager(); }
@@ -907,7 +907,7 @@ struct sat2goal::imp {
             if (aux) {
                 SASSERT(is_uninterp_const(atom));
                 SASSERT(m().is_bool(atom));
-                m_fmc->insert(to_app(atom)->get_decl());
+                m_fmc->hide(to_app(atom)->get_decl());
             }
         }
 
@@ -976,7 +976,7 @@ struct sat2goal::imp {
         
         virtual model_converter * translate(ast_translation & translator) {
             sat_model_converter * res = alloc(sat_model_converter, translator.to());
-            res->m_fmc = static_cast<filter_model_converter*>(m_fmc->translate(translator));
+            res->m_fmc = static_cast<generic_model_converter*>(m_fmc->translate(translator));
             for (expr* e : m_var2expr) 
                 res->m_var2expr.push_back(e ? translator(e) : nullptr);
             return res;
diff --git a/src/sat/tactic/sat_tactic.cpp b/src/sat/tactic/sat_tactic.cpp
index 3a5c414ef..7b48986c5 100644
--- a/src/sat/tactic/sat_tactic.cpp
+++ b/src/sat/tactic/sat_tactic.cpp
@@ -18,7 +18,6 @@ Notes:
 --*/
 #include "ast/ast_pp.h"
 #include "tactic/tactical.h"
-#include "tactic/filter_model_converter.h"
 #include "sat/tactic/goal2sat.h"
 #include "sat/sat_solver.h"
 #include "model/model_v2_pp.h"
diff --git a/src/smt/smt_solver.cpp b/src/smt/smt_solver.cpp
index 850621e67..7866f15e9 100644
--- a/src/smt/smt_solver.cpp
+++ b/src/smt/smt_solver.cpp
@@ -101,11 +101,11 @@ namespace smt {
             return m_context.find_mutexes(vars, mutexes);
         }
 
-        virtual void assert_expr(expr * t) {
+        virtual void assert_expr_core(expr * t) {
             m_context.assert_expr(t);
         }
 
-        virtual void assert_expr(expr * t, expr * a) {
+        virtual void assert_expr_core(expr * t, expr * a) {
             if (m_name2assertion.contains(a)) {
                 throw default_exception("named assertion defined twice");
             }
diff --git a/src/smt/tactic/smt_tactic.cpp b/src/smt/tactic/smt_tactic.cpp
index 57ac7b34b..77024dba6 100644
--- a/src/smt/tactic/smt_tactic.cpp
+++ b/src/smt/tactic/smt_tactic.cpp
@@ -23,7 +23,7 @@ Notes:
 #include "smt/params/smt_params_helper.hpp"
 #include "util/lp/lp_params.hpp"
 #include "ast/rewriter/rewriter_types.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/ast_util.h"
 #include "solver/solver2tactic.h"
 #include "smt/smt_solver.h"
@@ -169,7 +169,7 @@ public:
             expr_ref_vector clauses(m);
             expr2expr_map               bool2dep;
             ptr_vector<expr>            assumptions;
-            ref<filter_model_converter> fmc;
+            ref<generic_model_converter> fmc;
             if (in->unsat_core_enabled()) {
                 extract_clauses_and_dependencies(in, clauses, assumptions, bool2dep, fmc);
                 TRACE("mus", in->display_with_dependencies(tout);
diff --git a/src/smt/theory_arith.h b/src/smt/theory_arith.h
index 5f4e58a1b..ba08c82e2 100644
--- a/src/smt/theory_arith.h
+++ b/src/smt/theory_arith.h
@@ -1081,7 +1081,7 @@ namespace smt {
         virtual inf_eps_rational<inf_rational> maximize(theory_var v, expr_ref& blocker, bool& has_shared);
         virtual inf_eps_rational<inf_rational> value(theory_var v);
         virtual theory_var add_objective(app* term);
-        expr_ref mk_ge(filter_model_converter& fm, theory_var v, inf_numeral const& val);
+        expr_ref mk_ge(generic_model_converter& fm, theory_var v, inf_numeral const& val);
         void enable_record_conflict(expr* bound);
         void record_conflict(unsigned num_lits, literal const * lits, 
                           unsigned num_eqs, enode_pair const * eqs,
diff --git a/src/smt/theory_arith_aux.h b/src/smt/theory_arith_aux.h
index a1558e5e5..1d4c65f2d 100644
--- a/src/smt/theory_arith_aux.h
+++ b/src/smt/theory_arith_aux.h
@@ -23,7 +23,7 @@ Revision History:
 #include "smt/theory_arith.h"
 #include "smt/smt_farkas_util.h"
 #include "ast/rewriter/th_rewriter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 
 namespace smt {
 
@@ -1117,14 +1117,14 @@ namespace smt {
       This allows to handle inequalities with non-standard numbers.
     */
     template<typename Ext>
-    expr_ref theory_arith<Ext>::mk_ge(filter_model_converter& fm, theory_var v, inf_numeral const& val) {
+    expr_ref theory_arith<Ext>::mk_ge(generic_model_converter& fm, theory_var v, inf_numeral const& val) {
         ast_manager& m = get_manager();
         context& ctx = get_context();
         std::ostringstream strm;
         strm << val << " <= " << mk_pp(get_enode(v)->get_owner(), get_manager());
         app* b = m.mk_const(symbol(strm.str().c_str()), m.mk_bool_sort());
         if (!ctx.b_internalized(b)) {
-            fm.insert(b->get_decl());
+            fm.hide(b->get_decl());
             bool_var bv = ctx.mk_bool_var(b);
             ctx.set_var_theory(bv, get_id());
             // ctx.set_enode_flag(bv, true);
diff --git a/src/smt/theory_dense_diff_logic.h b/src/smt/theory_dense_diff_logic.h
index 980830447..e0de1ebd9 100644
--- a/src/smt/theory_dense_diff_logic.h
+++ b/src/smt/theory_dense_diff_logic.h
@@ -271,7 +271,7 @@ namespace smt {
         virtual inf_eps_rational<inf_rational> value(theory_var v);
         virtual theory_var add_objective(app* term);
         virtual expr_ref mk_gt(theory_var v, inf_eps const& val);
-        expr_ref mk_ge(filter_model_converter& fm, theory_var v, inf_eps const& val);
+        expr_ref mk_ge(generic_model_converter& fm, theory_var v, inf_eps const& val);
         
         // -----------------------------------
         //
diff --git a/src/smt/theory_dense_diff_logic_def.h b/src/smt/theory_dense_diff_logic_def.h
index 78fb4d03d..eef3cd068 100644
--- a/src/smt/theory_dense_diff_logic_def.h
+++ b/src/smt/theory_dense_diff_logic_def.h
@@ -1055,7 +1055,7 @@ namespace smt {
 
     template<typename Ext>
     expr_ref theory_dense_diff_logic<Ext>::mk_ge(
-        filter_model_converter& fm, theory_var v, inf_eps const& val) {
+        generic_model_converter& fm, theory_var v, inf_eps const& val) {
         return mk_ineq(v, val, false);
     }
 
diff --git a/src/smt/theory_diff_logic.h b/src/smt/theory_diff_logic.h
index 1ad239e58..6cd5ce872 100644
--- a/src/smt/theory_diff_logic.h
+++ b/src/smt/theory_diff_logic.h
@@ -324,7 +324,7 @@ namespace smt {
         virtual inf_eps maximize(theory_var v, expr_ref& blocker, bool& has_shared);
         virtual inf_eps value(theory_var v);
         virtual theory_var add_objective(app* term);
-        expr_ref mk_ge(filter_model_converter& fm, theory_var v, inf_eps const& val);
+        expr_ref mk_ge(generic_model_converter& fm, theory_var v, inf_eps const& val);
 
         bool internalize_objective(expr * n, rational const& m, rational& r, objective_term & objective);
 
diff --git a/src/smt/theory_diff_logic_def.h b/src/smt/theory_diff_logic_def.h
index 203dd24d2..0633b500f 100644
--- a/src/smt/theory_diff_logic_def.h
+++ b/src/smt/theory_diff_logic_def.h
@@ -1336,7 +1336,7 @@ expr_ref theory_diff_logic<Ext>::mk_gt(theory_var v, inf_eps const& val) {
 }
 
 template<typename Ext>
-expr_ref theory_diff_logic<Ext>::mk_ge(filter_model_converter& fm, theory_var v, inf_eps const& val) {
+expr_ref theory_diff_logic<Ext>::mk_ge(generic_model_converter& fm, theory_var v, inf_eps const& val) {
     return mk_ineq(v, val, false);
 }
 
diff --git a/src/smt/theory_lra.cpp b/src/smt/theory_lra.cpp
index 292d2ab0d..0cc25541b 100644
--- a/src/smt/theory_lra.cpp
+++ b/src/smt/theory_lra.cpp
@@ -36,7 +36,7 @@ Revision History:
 #include "smt/smt_model_generator.h"
 #include "smt/arith_eq_adapter.h"
 #include "util/nat_set.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 
 namespace lra_lp {
     enum bound_kind { lower_t, upper_t };
@@ -2417,7 +2417,7 @@ namespace smt {
             }
         }
 
-        expr_ref mk_ge(filter_model_converter& fm, theory_var v, inf_rational const& val) {
+        expr_ref mk_ge(generic_model_converter& fm, theory_var v, inf_rational const& val) {
             rational r = val.get_rational();
             bool is_strict =  val.get_infinitesimal().is_pos();
             app_ref b(m);
@@ -2429,7 +2429,7 @@ namespace smt {
                 b = a.mk_ge(mk_obj(v), a.mk_numeral(r, is_int));
             }
             if (!ctx().b_internalized(b)) {
-                fm.insert(b->get_decl());
+                fm.hide(b);
                 bool_var bv = ctx().mk_bool_var(b);
                 ctx().set_var_theory(bv, get_id());
                 // ctx().set_enode_flag(bv, true);
@@ -2620,7 +2620,7 @@ namespace smt {
     theory_var theory_lra::add_objective(app* term) {
         return m_imp->add_objective(term);
     }
-    expr_ref theory_lra::mk_ge(filter_model_converter& fm, theory_var v, inf_rational const& val) {
+    expr_ref theory_lra::mk_ge(generic_model_converter& fm, theory_var v, inf_rational const& val) {
         return m_imp->mk_ge(fm, v, val);
     }
 
diff --git a/src/smt/theory_lra.h b/src/smt/theory_lra.h
index 774ec15ad..d8cc655e9 100644
--- a/src/smt/theory_lra.h
+++ b/src/smt/theory_lra.h
@@ -89,7 +89,7 @@ namespace smt {
         virtual inf_eps value(theory_var);
         virtual inf_eps maximize(theory_var v, expr_ref& blocker, bool& has_shared); 
         virtual theory_var add_objective(app* term);
-        virtual expr_ref mk_ge(filter_model_converter& fm, theory_var v, inf_rational const& val);
+        virtual expr_ref mk_ge(generic_model_converter& fm, theory_var v, inf_rational const& val);
 
 
     };
diff --git a/src/smt/theory_opt.h b/src/smt/theory_opt.h
index 49f436ea5..2947d86c1 100644
--- a/src/smt/theory_opt.h
+++ b/src/smt/theory_opt.h
@@ -25,7 +25,7 @@ Notes:
 #ifndef THEORY_OPT_H_
 #define THEORY_OPT_H_
 
-class filter_model_converter;
+class generic_model_converter;
 namespace smt {
     class theory_opt {
     public:
diff --git a/src/smt/theory_wmaxsat.cpp b/src/smt/theory_wmaxsat.cpp
index 88ba89610..99715cbca 100644
--- a/src/smt/theory_wmaxsat.cpp
+++ b/src/smt/theory_wmaxsat.cpp
@@ -25,7 +25,7 @@ Notes:
 
 namespace smt {
 
-    theory_wmaxsat::theory_wmaxsat(ast_manager& m, filter_model_converter& mc):
+    theory_wmaxsat::theory_wmaxsat(ast_manager& m, generic_model_converter& mc):
         theory(m.mk_family_id("weighted_maxsat")),
         m_mc(mc),
         m_vars(m),
@@ -92,7 +92,7 @@ namespace smt {
         ast_manager& m = get_manager();
         app_ref var(m), wfml(m);
         var = m.mk_fresh_const("w", m.mk_bool_sort());
-        m_mc.insert(var->get_decl());
+        m_mc.hide(var);
         wfml = m.mk_or(var, fml);
         ctx.assert_expr(wfml);
         m_rweights.push_back(w);
diff --git a/src/smt/theory_wmaxsat.h b/src/smt/theory_wmaxsat.h
index 739a22c71..ff3006e11 100644
--- a/src/smt/theory_wmaxsat.h
+++ b/src/smt/theory_wmaxsat.h
@@ -22,7 +22,7 @@ Notes:
 
 #include "smt/smt_theory.h"
 #include "smt/smt_clause.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 
 namespace smt {
     class theory_wmaxsat : public theory {
@@ -32,7 +32,7 @@ namespace smt {
             void reset() { memset(this, 0, sizeof(*this)); }
             stats() { reset(); }
         };        
-        filter_model_converter&     m_mc;
+        generic_model_converter&     m_mc;
         mutable unsynch_mpz_manager m_mpz;
         app_ref_vector           m_vars;        // Auxiliary variables per soft clause
         expr_ref_vector          m_fmls;        // Formulas per soft clause
@@ -56,7 +56,7 @@ namespace smt {
         svector<bool>            m_assigned, m_enabled;
         stats                    m_stats;
     public:
-        theory_wmaxsat(ast_manager& m, filter_model_converter& mc);
+        theory_wmaxsat(ast_manager& m, generic_model_converter& mc);
         virtual ~theory_wmaxsat();
         void get_assignment(svector<bool>& result);
         expr* assert_weighted(expr* fml, rational const& w);
diff --git a/src/solver/combined_solver.cpp b/src/solver/combined_solver.cpp
index cc52c90cb..90a6cb7c8 100644
--- a/src/solver/combined_solver.cpp
+++ b/src/solver/combined_solver.cpp
@@ -164,7 +164,7 @@ public:
         m_solver2->set_produce_models(f);
     }
     
-    virtual void assert_expr(expr * t) {
+    virtual void assert_expr_core(expr * t) {
         if (m_check_sat_executed)
             switch_inc_mode();
         m_solver1->assert_expr(t);
@@ -172,7 +172,7 @@ public:
             m_solver2->assert_expr(t);
     }
 
-    virtual void assert_expr(expr * t, expr * a) {
+    virtual void assert_expr_core(expr * t, expr * a) {
         if (m_check_sat_executed)
             switch_inc_mode();
         m_solver1->assert_expr(t, a);
diff --git a/src/solver/solver.cpp b/src/solver/solver.cpp
index de0834b9d..8f1287dab 100644
--- a/src/solver/solver.cpp
+++ b/src/solver/solver.cpp
@@ -182,13 +182,26 @@ bool solver::is_literal(ast_manager& m, expr* e) {
     return is_uninterp_const(e) || (m.is_not(e, e) && is_uninterp_const(e));
 }
 
-#if 0
-expr_ref solver::lookahead(expr_ref_vector const& candidates) {
-    std::cout << "lookahead: " << candidates.size() << "\n";
-    INVOKE_DEBUGGER();
-    ast_manager& m = candidates.get_manager();
-    return expr_ref(m.mk_true(), m);
+
+void solver::assert_expr(expr* f) {
+    expr_ref fml(f, get_manager());
+    if (mc0()) {
+        (*mc0())(fml);        
+    }
+    assert_expr_core(fml);    
 }
-#endif
 
+void solver::assert_expr(expr* f, expr* t) {
+    // let mc0 be the model converter associated with the solver
+    // that converts models to their "real state".
+    ast_manager& m = get_manager();
+    expr_ref fml(f, m);
+    expr_ref a(t, m);
+
+    if (mc0()) {
+        (*mc0())(fml);        
+        // (*mc0())(a);        
+    }
+    assert_expr_core(fml, a);    
+}
 
diff --git a/src/solver/solver.h b/src/solver/solver.h
index 713434d7c..780a55cf5 100644
--- a/src/solver/solver.h
+++ b/src/solver/solver.h
@@ -80,14 +80,16 @@ public:
     /**
        \brief Add a new formula to the assertion stack.
     */
-    virtual void assert_expr(expr * t) = 0;
+    void assert_expr(expr* f);
+
+    virtual void assert_expr_core(expr * t) = 0;
 
     void assert_expr(expr_ref_vector const& ts) { 
-        for (unsigned i = 0; i < ts.size(); ++i) assert_expr(ts[i]); 
+        for (expr* e : ts) assert_expr(e);
     }
 
     void assert_expr(ptr_vector<expr> const& ts) { 
-        for (unsigned i = 0; i < ts.size(); ++i) assert_expr(ts[i]); 
+        for (expr* e : ts) assert_expr(e);
     }
 
     /**
@@ -95,7 +97,10 @@ public:
        The propositional variable \c a is used to track the use of \c t in a proof
        of unsatisfiability.
     */
-    virtual void assert_expr(expr * t, expr * a) = 0;
+
+    void assert_expr(expr * t, expr* a);
+
+    virtual void assert_expr_core(expr * t, expr * a) = 0;
 
     /**
        \brief Add a lemma to the assertion stack. A lemma is assumed to be a consequence of already
@@ -210,11 +215,13 @@ public:
         ~scoped_push() { if (!m_nopop) s.pop(1); }
         void disable_pop() { m_nopop = true; }
     };
+
  
 protected:
 
     virtual lbool get_consequences_core(expr_ref_vector const& asms, expr_ref_vector const& vars, expr_ref_vector& consequences);
 
+
     bool is_literal(ast_manager& m, expr* e);
 
 };
diff --git a/src/solver/solver2tactic.cpp b/src/solver/solver2tactic.cpp
index eea3aa9c5..a44463a75 100644
--- a/src/solver/solver2tactic.cpp
+++ b/src/solver/solver2tactic.cpp
@@ -19,13 +19,13 @@ Notes:
 
 #include "solver/solver.h"
 #include "tactic/tactic.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "solver/solver2tactic.h"
 #include "ast/ast_util.h"
 
 typedef obj_map<expr, expr *> expr2expr_map;
 
-void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clauses, ptr_vector<expr>& assumptions, expr2expr_map& bool2dep, ref<filter_model_converter>& fmc) {
+void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clauses, ptr_vector<expr>& assumptions, expr2expr_map& bool2dep, ref<generic_model_converter>& fmc) {
     expr2expr_map dep2bool;
     ptr_vector<expr> deps;
     ast_manager& m = g->m();
@@ -65,9 +65,9 @@ void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clause
                         bool2dep.insert(b, d);
                         assumptions.push_back(b);
                         if (!fmc) {
-                            fmc = alloc(filter_model_converter, m);
+                            fmc = alloc(generic_model_converter, m);
                         }
-                        fmc->insert(to_app(b)->get_decl());
+                        fmc->hide(to_app(b)->get_decl());
                     }
                     clause.push_back(m.mk_not(b));
                 }
@@ -110,7 +110,7 @@ public:
         expr_ref_vector clauses(m);
         expr2expr_map               bool2dep;
         ptr_vector<expr>            assumptions;
-        ref<filter_model_converter> fmc;
+        ref<generic_model_converter> fmc;
         extract_clauses_and_dependencies(in, clauses, assumptions, bool2dep, fmc);
         ref<solver> local_solver = m_solver->translate(m, m_params);
         local_solver->assert_expr(clauses);
diff --git a/src/solver/solver2tactic.h b/src/solver/solver2tactic.h
index 647a1cee4..8c6466ddb 100644
--- a/src/solver/solver2tactic.h
+++ b/src/solver/solver2tactic.h
@@ -20,11 +20,11 @@ Notes:
 #define SOLVER2TACTIC_H_
 
 #include "tactic/tactic.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 class solver;
 
 tactic * mk_solver2tactic(solver* s);
 
-void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clauses, ptr_vector<expr>& assumptions, obj_map<expr, expr*>& bool2dep, ref<filter_model_converter>& fmc);
+void extract_clauses_and_dependencies(goal_ref const& g, expr_ref_vector& clauses, ptr_vector<expr>& assumptions, obj_map<expr, expr*>& bool2dep, ref<generic_model_converter>& fmc);
 
 #endif
diff --git a/src/solver/solver_na2as.cpp b/src/solver/solver_na2as.cpp
index 2628380c5..ae4014c7f 100644
--- a/src/solver/solver_na2as.cpp
+++ b/src/solver/solver_na2as.cpp
@@ -30,9 +30,9 @@ solver_na2as::solver_na2as(ast_manager & m):
 
 solver_na2as::~solver_na2as() {}
 
-void solver_na2as::assert_expr(expr * t, expr * a) {
+void solver_na2as::assert_expr_core(expr * t, expr * a) {
     if (a == 0) {
-        assert_expr(t);
+        assert_expr_core(t);
     }
     else {
         SASSERT(is_uninterp_const(a));
@@ -41,7 +41,7 @@ void solver_na2as::assert_expr(expr * t, expr * a) {
         m_assumptions.push_back(a);
         expr_ref new_t(m);
         new_t = m.mk_implies(a, t);
-        assert_expr(new_t);
+        assert_expr_core(new_t);
     }
 }
 
diff --git a/src/solver/solver_na2as.h b/src/solver/solver_na2as.h
index 3e726be12..061d62aee 100644
--- a/src/solver/solver_na2as.h
+++ b/src/solver/solver_na2as.h
@@ -34,8 +34,8 @@ public:
     solver_na2as(ast_manager & m);
     virtual ~solver_na2as();
 
-    virtual void assert_expr(expr * t, expr * a);
-    virtual void assert_expr(expr * t) = 0;
+    void assert_expr_core(expr * t, expr * a) override;
+    virtual void assert_expr_core(expr * t) = 0;
     
     // Subclasses of solver_na2as should redefine the following *_core methods instead of these ones.
     virtual lbool check_sat(unsigned num_assumptions, expr * const * assumptions);
diff --git a/src/solver/solver_pool.cpp b/src/solver/solver_pool.cpp
index 3c7837ad5..1b7203351 100644
--- a/src/solver/solver_pool.cpp
+++ b/src/solver/solver_pool.cpp
@@ -49,7 +49,7 @@ public:
         m_in_delayed_scope(false),
         m_dump_counter(0) {
         if (is_virtual()) {
-            solver_na2as::assert_expr(m.mk_true(), pred);
+            solver_na2as::assert_expr_core(m.mk_true(), pred);
         }
     }
 
@@ -191,7 +191,7 @@ public:
         }
     }
     
-    virtual void assert_expr(expr * e) {
+    virtual void assert_expr_core(expr * e) {
         SASSERT(!m_pushed || get_scope_level() > 0);
         if (m.is_true(e)) return; 
         if (m_in_delayed_scope) {
diff --git a/src/solver/tactic2solver.cpp b/src/solver/tactic2solver.cpp
index dd2f42e7a..35fe9cf8e 100644
--- a/src/solver/tactic2solver.cpp
+++ b/src/solver/tactic2solver.cpp
@@ -54,7 +54,7 @@ public:
 
     virtual void set_produce_models(bool f) { m_produce_models = f; }
 
-    virtual void assert_expr(expr * t);
+    virtual void assert_expr_core(expr * t);
     virtual void assert_lemma(expr * t);
 
     virtual void push_core();
@@ -112,7 +112,7 @@ void tactic2solver::collect_param_descrs(param_descrs & r) {
         m_tactic->collect_param_descrs(r);
 }
 
-void tactic2solver::assert_expr(expr * t) {
+void tactic2solver::assert_expr_core(expr * t) {
     m_assertions.push_back(t);
     m_result = 0;
 }
diff --git a/src/tactic/CMakeLists.txt b/src/tactic/CMakeLists.txt
index 74379b30f..04900fcbe 100644
--- a/src/tactic/CMakeLists.txt
+++ b/src/tactic/CMakeLists.txt
@@ -2,7 +2,6 @@ z3_add_component(tactic
   SOURCES
     equiv_proof_converter.cpp
     extension_model_converter.cpp
-    filter_model_converter.cpp
     generic_model_converter.cpp
     goal.cpp
     goal_num_occurs.cpp
diff --git a/src/tactic/arith/card2bv_tactic.cpp b/src/tactic/arith/card2bv_tactic.cpp
index 932898bd1..2e4782b2c 100644
--- a/src/tactic/arith/card2bv_tactic.cpp
+++ b/src/tactic/arith/card2bv_tactic.cpp
@@ -23,7 +23,7 @@ Notes:
 #include "ast/rewriter/pb2bv_rewriter.h"
 #include "ast/ast_util.h"
 #include "ast/ast_pp.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 
 class card2bv_tactic : public tactic {
     ast_manager &              m;
@@ -89,9 +89,9 @@ public:
         
         func_decl_ref_vector const& fns = rw2.fresh_constants();
         if (!fns.empty()) {
-            filter_model_converter* filter = alloc(filter_model_converter, m);
+            generic_model_converter* filter = alloc(generic_model_converter, m);
             for (unsigned i = 0; i < fns.size(); ++i) {
-                filter->insert(fns[i]);
+                filter->hide(fns[i]);
             }
             mc = filter;
         }
diff --git a/src/tactic/arith/degree_shift_tactic.cpp b/src/tactic/arith/degree_shift_tactic.cpp
index 80b7a416c..519fec742 100644
--- a/src/tactic/arith/degree_shift_tactic.cpp
+++ b/src/tactic/arith/degree_shift_tactic.cpp
@@ -20,7 +20,6 @@ Revision History:
 
 --*/
 #include "tactic/tactical.h"
-#include "tactic/filter_model_converter.h"
 #include "tactic/generic_model_converter.h"
 #include "util/cooperate.h"
 #include "ast/arith_decl_plugin.h"
@@ -197,12 +196,10 @@ class degree_shift_tactic : public tactic {
 
         void prepare_substitution(model_converter_ref & mc) {
             SASSERT(!m_var2degree.empty());
-            filter_model_converter * fmc = 0;
             generic_model_converter * xmc = 0;
             if (m_produce_models) {
-                fmc = alloc(filter_model_converter, m);
                 xmc = alloc(generic_model_converter, m);
-                mc = concat(fmc, xmc);
+                mc = xmc;
             }
             for (auto const& kv : m_var2degree) {
                 SASSERT(kv.m_value.is_int());
@@ -211,7 +208,7 @@ class degree_shift_tactic : public tactic {
                 m_pinned.push_back(fresh);
                 m_var2var.insert(kv.m_key, fresh);
                 if (m_produce_models) {
-                    fmc->insert(fresh->get_decl());
+                    xmc->hide(fresh->get_decl());
                     xmc->add(kv.m_key->get_decl(), mk_power(fresh, rational(1)/kv.m_value));
                 }
                 if (m_produce_proofs) {
diff --git a/src/tactic/arith/lia2pb_tactic.cpp b/src/tactic/arith/lia2pb_tactic.cpp
index d303463db..a339db51b 100644
--- a/src/tactic/arith/lia2pb_tactic.cpp
+++ b/src/tactic/arith/lia2pb_tactic.cpp
@@ -21,7 +21,7 @@ Revision History:
 #include "ast/rewriter/th_rewriter.h"
 #include "ast/for_each_expr.h"
 #include "tactic/extension_model_converter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/arith_decl_plugin.h"
 #include "ast/expr_substitution.h"
 #include "ast/ast_smt2_pp.h"
@@ -225,10 +225,10 @@ class lia2pb_tactic : public tactic {
                 throw tactic_exception("lia2pb failed, number of necessary bits exceeds specified threshold (use option :lia2pb-total-bits to increase threshold)");
             
             extension_model_converter * mc1 = 0;
-            filter_model_converter    * mc2 = 0;
+            generic_model_converter    * mc2 = 0;
             if (m_produce_models) {
                 mc1 = alloc(extension_model_converter, m);
-                mc2 = alloc(filter_model_converter, m);
+                mc2 = alloc(generic_model_converter, m);
                 mc  = concat(mc2, mc1);
             }
             
@@ -259,7 +259,7 @@ class lia2pb_tactic : public tactic {
                         else
                             def_args.push_back(m_util.mk_mul(m_util.mk_numeral(a, true), x_prime));
                         if (m_produce_models)
-                            mc2->insert(x_prime->get_decl());
+                            mc2->hide(x_prime->get_decl());
                         a *= rational(2);
                     }
                     SASSERT(def_args.size() > 1);
diff --git a/src/tactic/arith/nla2bv_tactic.cpp b/src/tactic/arith/nla2bv_tactic.cpp
index 6f5f49aee..00cb02cf6 100644
--- a/src/tactic/arith/nla2bv_tactic.cpp
+++ b/src/tactic/arith/nla2bv_tactic.cpp
@@ -27,7 +27,7 @@ Notes:
 #include "tactic/arith/bv2int_rewriter.h"
 #include "tactic/arith/bv2real_rewriter.h"
 #include "tactic/extension_model_converter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "tactic/arith/bound_manager.h"
 #include "util/obj_pair_hashtable.h"
 #include "ast/ast_smt2_pp.h"
@@ -60,7 +60,7 @@ class nla2bv_tactic : public tactic {
         expr_ref_vector             m_trail;
         unsigned                    m_num_bits;
         unsigned                    m_default_bv_size;
-        filter_model_converter_ref  m_fmc;
+        generic_model_converter_ref  m_fmc;
         
     public:
         imp(ast_manager & m, params_ref const& p):
@@ -86,7 +86,7 @@ class nla2bv_tactic : public tactic {
             TRACE("nla2bv", g.display(tout);
                   tout << "Muls: " << count_mul(g) << "\n";
                   );
-            m_fmc = alloc(filter_model_converter, m_manager);
+            m_fmc = alloc(generic_model_converter, m_manager);
             m_bounds(g);
             collect_power2(g);
             if(!collect_vars(g)) {
@@ -104,7 +104,7 @@ class nla2bv_tactic : public tactic {
                 evc->insert(m_vars[i].get(), m_defs[i].get());
             }
             for (unsigned i = 0; i < m_bv2real.num_aux_decls(); ++i) {
-                m_fmc->insert(m_bv2real.get_aux_decl(i));
+                m_fmc->hide(m_bv2real.get_aux_decl(i));
             }        
             IF_VERBOSE(TACTIC_VERBOSITY_LVL, verbose_stream() << "(nla->bv :sat-preserving " << m_is_sat_preserving << ")\n";);
             TRACE("nla2bv_verbose", g.display(tout););
@@ -233,7 +233,7 @@ class nla2bv_tactic : public tactic {
             bv_sort = m_bv.mk_sort(num_bits);
             std::string name = n->get_decl()->get_name().str();
             s_bv = m_manager.mk_fresh_const(name.c_str(), bv_sort);
-            m_fmc->insert(to_app(s_bv)->get_decl());
+            m_fmc->hide(s_bv);
             s_bv = m_bv.mk_bv2int(s_bv);
             if (low) {
                 if (!(*low).is_zero()) {
@@ -271,8 +271,8 @@ class nla2bv_tactic : public tactic {
             s = m_manager.mk_fresh_const(name.c_str(), bv_sort);
             name += "_r";
             t = m_manager.mk_fresh_const(name.c_str(), bv_sort);
-            m_fmc->insert(to_app(s)->get_decl());
-            m_fmc->insert(to_app(t)->get_decl());
+            m_fmc->hide(s);
+            m_fmc->hide(t);
             s_bv = m_bv2real.mk_bv2real(s, t);
             m_trail.push_back(s_bv);
             m_subst.insert(n, s_bv);
diff --git a/src/tactic/arith/normalize_bounds_tactic.cpp b/src/tactic/arith/normalize_bounds_tactic.cpp
index 2b3ff5ab0..90f92f3f7 100644
--- a/src/tactic/arith/normalize_bounds_tactic.cpp
+++ b/src/tactic/arith/normalize_bounds_tactic.cpp
@@ -22,7 +22,7 @@ Revision History:
 #include "tactic/arith/bound_manager.h"
 #include "ast/rewriter/th_rewriter.h"
 #include "tactic/extension_model_converter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/arith_decl_plugin.h"
 #include "ast/expr_substitution.h"
 #include "ast/ast_smt2_pp.h"
@@ -99,10 +99,10 @@ class normalize_bounds_tactic : public tactic {
             }
             
             extension_model_converter * mc1 = 0;
-            filter_model_converter   * mc2  = 0;
+            generic_model_converter   * mc2  = 0;
             if (produce_models) {
                 mc1 = alloc(extension_model_converter, m);
-                mc2 = alloc(filter_model_converter, m);
+                mc2 = alloc(generic_model_converter, m);
                 mc  = concat(mc2, mc1);
             }
             
@@ -121,7 +121,7 @@ class normalize_bounds_tactic : public tactic {
                     subst.insert(x, def);
                     if (produce_models) {
                         mc1->insert(to_app(x)->get_decl(), def);
-                        mc2->insert(x_prime->get_decl());
+                        mc2->hide(x_prime->get_decl());
                     }
                 }
             }
diff --git a/src/tactic/arith/pb2bv_tactic.cpp b/src/tactic/arith/pb2bv_tactic.cpp
index 259cbc0c8..f391e2a17 100644
--- a/src/tactic/arith/pb2bv_tactic.cpp
+++ b/src/tactic/arith/pb2bv_tactic.cpp
@@ -26,7 +26,7 @@ Notes:
 #include "util/trace.h"
 #include "ast/ast_smt2_pp.h"
 #include "ast/expr_substitution.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "tactic/arith/pb2bv_model_converter.h"
 #include "tactic/arith/pb2bv_tactic.h"
 #include "ast/ast_pp.h"
@@ -949,15 +949,13 @@ private:
                 g->update(idx, new_exprs[idx].get(), 0, (m_produce_unsat_cores) ? new_deps[idx].get() : g->dep(idx));
 
             if (m_produce_models) {
-                filter_model_converter * mc1 = alloc(filter_model_converter, m);
-                obj_map<func_decl, expr*>::iterator it  = m_const2bit.begin();
-                obj_map<func_decl, expr*>::iterator end = m_const2bit.end();
-                for (; it != end; ++it)
-                    mc1->insert(to_app(it->m_value)->get_decl());
+                generic_model_converter * mc1 = alloc(generic_model_converter, m);
+                for (auto const& kv : m_const2bit) 
+                    mc1->hide(kv.m_value);
                 // store temp int constants in the filter
                 unsigned num_temps = m_temporary_ints.size();
                 for (unsigned i = 0; i < num_temps; i++)
-                    mc1->insert(to_app(m_temporary_ints.get(i))->get_decl());
+                    mc1->hide(m_temporary_ints.get(i));
                 pb2bv_model_converter * mc2 = alloc(pb2bv_model_converter, m, m_const2bit, m_bm);
                 mc = concat(mc1, mc2);                
             }
diff --git a/src/tactic/arith/purify_arith_tactic.cpp b/src/tactic/arith/purify_arith_tactic.cpp
index 7e89794ce..144a13bcd 100644
--- a/src/tactic/arith/purify_arith_tactic.cpp
+++ b/src/tactic/arith/purify_arith_tactic.cpp
@@ -27,7 +27,7 @@ Revision History:
 #include "tactic/core/nnf_tactic.h"
 #include "tactic/core/simplify_tactic.h"
 #include "ast/rewriter/th_rewriter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "tactic/extension_model_converter.h"
 #include "ast/ast_smt2_pp.h"
 #include "ast/rewriter/expr_replacer.h"
@@ -764,17 +764,15 @@ struct purify_arith_proc {
             m_goal.assert_expr(r.cfg().m_new_cnstrs.get(i), m_produce_proofs ? r.cfg().m_new_cnstr_prs.get(i) : 0, 0);
         }
         
-        // add filter_model_converter to eliminate auxiliary variables from model
+        // add generic_model_converter to eliminate auxiliary variables from model
         if (produce_models) {
-            filter_model_converter * fmc = alloc(filter_model_converter, m());
+            generic_model_converter * fmc = alloc(generic_model_converter, m());
             mc = fmc;
             obj_map<app, expr*> & f2v = r.cfg().m_app2fresh;
-            obj_map<app, expr*>::iterator it  = f2v.begin();
-            obj_map<app, expr*>::iterator end = f2v.end();
-            for (; it != end; ++it) {
-                app * v = to_app(it->m_value);
+            for (auto const& kv : f2v) {
+                app * v = to_app(kv.m_value);
                 SASSERT(is_uninterp_const(v));
-                fmc->insert(v->get_decl());
+                fmc->hide(v->get_decl());
             }
         }
         if (produce_models && !m_sin_cos.empty()) {
diff --git a/src/tactic/arith/recover_01_tactic.cpp b/src/tactic/arith/recover_01_tactic.cpp
index d3b9ecc3e..bd03f6901 100644
--- a/src/tactic/arith/recover_01_tactic.cpp
+++ b/src/tactic/arith/recover_01_tactic.cpp
@@ -33,7 +33,7 @@ Revision History:
 #include "tactic/tactical.h"
 #include "ast/rewriter/th_rewriter.h"
 #include "tactic/extension_model_converter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/arith_decl_plugin.h"
 #include "ast/expr_substitution.h"
 #include "util/dec_ref_util.h"
@@ -113,7 +113,7 @@ class recover_01_tactic : public tactic {
         
         // temporary fields used by operator() and process
         extension_model_converter * mc1;
-        filter_model_converter *    mc2;
+        generic_model_converter *    mc2;
         expr_substitution *         subst;
         goal_ref                    new_goal;
         obj_map<expr, expr *>       bool2int;
@@ -205,7 +205,7 @@ class recover_01_tactic : public tactic {
                 expr * bool_def = m.mk_eq(var, m_util.mk_numeral(rational(1), true));
                 subst->insert(atom, bool_def);
                 if (m_produce_models) {
-                    mc2->insert(to_app(var)->get_decl());
+                    mc2->hide(to_app(var)->get_decl());
                     mc1->insert(to_app(atom)->get_decl(), bool_def);
                 }
                 m.inc_ref(atom);
@@ -329,7 +329,7 @@ class recover_01_tactic : public tactic {
             
             if (m_produce_models) {
                 mc1 = alloc(extension_model_converter, m);
-                mc2 = alloc(filter_model_converter, m);
+                mc2 = alloc(generic_model_converter, m);
                 mc  = concat(mc2, mc1);
             }
             
diff --git a/src/tactic/bv/bv_size_reduction_tactic.cpp b/src/tactic/bv/bv_size_reduction_tactic.cpp
index 9401f74c1..c62e1177d 100644
--- a/src/tactic/bv/bv_size_reduction_tactic.cpp
+++ b/src/tactic/bv/bv_size_reduction_tactic.cpp
@@ -25,7 +25,7 @@ Notes:
 #include "ast/bv_decl_plugin.h"
 #include "ast/rewriter/expr_replacer.h"
 #include "tactic/extension_model_converter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/ast_smt2_pp.h"
 
 class bv_size_reduction_tactic : public tactic {
@@ -60,7 +60,7 @@ struct bv_size_reduction_tactic::imp {
     obj_map<app, numeral>     m_unsigned_lowers;
     obj_map<app, numeral>     m_unsigned_uppers;
     ref<bv_size_reduction_mc> m_mc;
-    filter_model_converter_ref m_fmc;
+    generic_model_converter_ref m_fmc;
     scoped_ptr<expr_replacer> m_replacer;
     bool                      m_produce_models;
 
@@ -269,9 +269,9 @@ struct bv_size_reduction_tactic::imp {
                                     m_mc = alloc(bv_size_reduction_mc, m);
                                 m_mc->insert(v->get_decl(), new_def);
                                 if (!m_fmc && new_const) 
-                                    m_fmc = alloc(filter_model_converter, m);
+                                    m_fmc = alloc(generic_model_converter, m);
                                 if (new_const) 
-                                    m_fmc->insert(new_const->get_decl());
+                                    m_fmc->hide(new_const);
                             }
                             num_reduced++;
                         }
@@ -335,9 +335,9 @@ struct bv_size_reduction_tactic::imp {
                                 m_mc = alloc(bv_size_reduction_mc, m);
                             m_mc->insert(v->get_decl(), new_def);
                             if (!m_fmc && new_const) 
-                                m_fmc = alloc(filter_model_converter, m);
+                                m_fmc = alloc(generic_model_converter, m);
                             if (new_const) 
-                                m_fmc->insert(new_const->get_decl());
+                                m_fmc->hide(new_const);
                         }
                         num_reduced++;
                         TRACE("bv_size_reduction", tout << "New definition = " << mk_ismt2_pp(new_def, m) << "\n";);
diff --git a/src/tactic/bv/bvarray2uf_rewriter.cpp b/src/tactic/bv/bvarray2uf_rewriter.cpp
index b92092739..1d96ffc35 100644
--- a/src/tactic/bv/bvarray2uf_rewriter.cpp
+++ b/src/tactic/bv/bvarray2uf_rewriter.cpp
@@ -120,7 +120,7 @@ func_decl_ref bvarray2uf_rewriter_cfg::mk_uf_for_array(expr * e) {
                                   m_array_util.mk_as_array(bv_f));
             }
             else if (m_fmc)
-                m_fmc->insert(bv_f);
+                m_fmc->hide(bv_f);
             m_arrays_fs.insert(e, bv_f);
             m_manager.inc_ref(e);
             m_manager.inc_ref(bv_f);
@@ -193,10 +193,10 @@ br_status bvarray2uf_rewriter_cfg::reduce_app(func_decl * f, unsigned num, expr
             if (is_uninterp_const(e)) {
                 if (m_emc)
                     m_emc->insert(e->get_decl(),
-                        m_array_util.mk_as_array(bv_f));
+                                  m_array_util.mk_as_array(bv_f));
             }
             else if (m_fmc)
-                m_fmc->insert(bv_f);
+                m_fmc->hide(bv_f);
             m_arrays_fs.insert(e, bv_f);
             m_manager.inc_ref(e);
             m_manager.inc_ref(bv_f);
diff --git a/src/tactic/bv/bvarray2uf_rewriter.h b/src/tactic/bv/bvarray2uf_rewriter.h
index bc4014b5b..0fe5762ae 100644
--- a/src/tactic/bv/bvarray2uf_rewriter.h
+++ b/src/tactic/bv/bvarray2uf_rewriter.h
@@ -22,7 +22,7 @@ Notes:
 
 #include "ast/rewriter/rewriter.h"
 #include "tactic/extension_model_converter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 
 class bvarray2uf_rewriter_cfg : public default_rewriter_cfg {
     ast_manager       & m_manager;
@@ -31,7 +31,7 @@ class bvarray2uf_rewriter_cfg : public default_rewriter_cfg {
     bv_util             m_bv_util;
     array_util          m_array_util;
     extension_model_converter * m_emc;
-    filter_model_converter * m_fmc;
+    generic_model_converter * m_fmc;
 
     obj_map<expr, func_decl*> m_arrays_fs;
 
@@ -59,7 +59,7 @@ public:
 
     expr_ref_vector extra_assertions;
 
-    void set_mcs(extension_model_converter * emc, filter_model_converter * fmc) { m_emc = emc; m_fmc = fmc; }
+    void set_mcs(extension_model_converter * emc, generic_model_converter * fmc) { m_emc = emc; m_fmc = fmc; }
 
 protected:
     sort * get_index_sort(expr * e);
@@ -79,7 +79,7 @@ struct bvarray2uf_rewriter : public rewriter_tpl<bvarray2uf_rewriter_cfg> {
         m_cfg(m, p) {
     }
 
-    void set_mcs(extension_model_converter * emc, filter_model_converter * fmc) { m_cfg.set_mcs(emc, fmc); }
+    void set_mcs(extension_model_converter * emc, generic_model_converter * fmc) { m_cfg.set_mcs(emc, fmc); }
 };
 
 #endif
diff --git a/src/tactic/bv/bvarray2uf_tactic.cpp b/src/tactic/bv/bvarray2uf_tactic.cpp
index 87f43ae8d..af74a2d8f 100644
--- a/src/tactic/bv/bvarray2uf_tactic.cpp
+++ b/src/tactic/bv/bvarray2uf_tactic.cpp
@@ -21,7 +21,7 @@ Notes:
 #include "ast/bv_decl_plugin.h"
 #include "ast/rewriter/expr_replacer.h"
 #include "tactic/extension_model_converter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/ast_smt2_pp.h"
 
 #include "tactic/bv/bvarray2uf_tactic.h"
@@ -69,7 +69,7 @@ class bvarray2uf_tactic : public tactic {
 
             if (m_produce_models) {
                 extension_model_converter * emc = alloc(extension_model_converter, m_manager);
-                filter_model_converter * fmc = alloc(filter_model_converter, m_manager);
+                generic_model_converter * fmc = alloc(generic_model_converter, m_manager);
                 mc = concat(emc, fmc);
                 m_rw.set_mcs(emc, fmc);
             }
diff --git a/src/tactic/bv/dt2bv_tactic.cpp b/src/tactic/bv/dt2bv_tactic.cpp
index 2b1aa0fdd..6a1de26fe 100644
--- a/src/tactic/bv/dt2bv_tactic.cpp
+++ b/src/tactic/bv/dt2bv_tactic.cpp
@@ -21,11 +21,11 @@ Revision History:
 
 #include "tactic/bv/dt2bv_tactic.h"
 #include "tactic/tactical.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/datatype_decl_plugin.h"
 #include "ast/bv_decl_plugin.h"
 #include "ast/rewriter/rewriter_def.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "tactic/extension_model_converter.h"
 #include "ast/rewriter/var_subst.h"
 #include "ast/ast_util.h"
@@ -135,7 +135,7 @@ public:
             m_fd_sorts.remove(s);
         if (!m_fd_sorts.empty()) {
             ref<extension_model_converter> ext = alloc(extension_model_converter, m);
-            ref<filter_model_converter> filter = alloc(filter_model_converter, m);
+            ref<generic_model_converter> filter = alloc(generic_model_converter, m);
             enum2bv_rewriter rw(m, m_params);
             rw.set_is_fd(&m_is_fd);            
             expr_ref   new_curr(m);
@@ -153,7 +153,7 @@ public:
             for (expr* b : bounds) 
                 g->assert_expr(b);
             for (auto const& kv : rw.enum2bv()) 
-                filter->insert(kv.m_value);
+                filter->hide(kv.m_value);
             for (auto const& kv : rw.enum2def()) 
                 ext->insert(kv.m_key, kv.m_value);
             
diff --git a/src/tactic/bv/elim_small_bv_tactic.cpp b/src/tactic/bv/elim_small_bv_tactic.cpp
index ab4b3920d..a0f78154f 100644
--- a/src/tactic/bv/elim_small_bv_tactic.cpp
+++ b/src/tactic/bv/elim_small_bv_tactic.cpp
@@ -18,7 +18,7 @@ Revision History:
 --*/
 #include "tactic/tactical.h"
 #include "ast/rewriter/rewriter_def.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "util/cooperate.h"
 #include "ast/bv_decl_plugin.h"
 #include "ast/used_vars.h"
@@ -35,7 +35,7 @@ class elim_small_bv_tactic : public tactic {
         params_ref                  m_params;
         bv_util                     m_util;
         th_rewriter                 m_simp;
-        ref<filter_model_converter> m_mc;
+        ref<generic_model_converter> m_mc;
         goal *                      m_goal;
         unsigned                    m_max_bits;
         unsigned long long          m_max_steps;
diff --git a/src/tactic/core/blast_term_ite_tactic.cpp b/src/tactic/core/blast_term_ite_tactic.cpp
index ae0ea019b..698da8498 100644
--- a/src/tactic/core/blast_term_ite_tactic.cpp
+++ b/src/tactic/core/blast_term_ite_tactic.cpp
@@ -19,7 +19,6 @@ Notes:
 #include "tactic/tactical.h"
 #include "ast/normal_forms/defined_names.h"
 #include "ast/rewriter/rewriter_def.h"
-#include "tactic/filter_model_converter.h"
 #include "util/cooperate.h"
 #include "ast/scoped_proof.h"
 
diff --git a/src/tactic/core/elim_term_ite_tactic.cpp b/src/tactic/core/elim_term_ite_tactic.cpp
index 79526a101..d6fb8a091 100644
--- a/src/tactic/core/elim_term_ite_tactic.cpp
+++ b/src/tactic/core/elim_term_ite_tactic.cpp
@@ -20,7 +20,7 @@ Notes:
 #include "tactic/tactical.h"
 #include "ast/normal_forms/defined_names.h"
 #include "ast/rewriter/rewriter_def.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "util/cooperate.h"
 
 class elim_term_ite_tactic : public tactic {
@@ -28,7 +28,7 @@ class elim_term_ite_tactic : public tactic {
     struct rw_cfg : public default_rewriter_cfg {
         ast_manager &               m;
         defined_names               m_defined_names;
-        ref<filter_model_converter> m_mc;
+        ref<generic_model_converter> m_mc;
         goal *                      m_goal;
         unsigned long long          m_max_memory; // in bytes
         bool                        m_produce_models;
@@ -55,8 +55,8 @@ class elim_term_ite_tactic : public tactic {
                 m_num_fresh++;
                 if (m_produce_models) {
                     if (!m_mc)
-                        m_mc = alloc(filter_model_converter, m);
-                    m_mc->insert(_result->get_decl());
+                        m_mc = alloc(generic_model_converter, m);
+                    m_mc->hide(_result->get_decl());
                 }
             }
             result = _result.get();
diff --git a/src/tactic/core/elim_uncnstr_tactic.cpp b/src/tactic/core/elim_uncnstr_tactic.cpp
index 614b20a10..aa5d55a8c 100644
--- a/src/tactic/core/elim_uncnstr_tactic.cpp
+++ b/src/tactic/core/elim_uncnstr_tactic.cpp
@@ -18,7 +18,6 @@ Notes:
 --*/
 #include "tactic/tactical.h"
 #include "tactic/generic_model_converter.h"
-#include "tactic/filter_model_converter.h"
 #include "ast/rewriter/rewriter_def.h"
 #include "ast/arith_decl_plugin.h"
 #include "ast/bv_decl_plugin.h"
@@ -873,9 +872,9 @@ class elim_uncnstr_tactic : public tactic {
                         app_ref_vector & fresh_vars = m_rw->cfg().m_fresh_vars;
                         m_num_elim_apps = fresh_vars.size();
                         if (produce_models && !fresh_vars.empty()) {
-                            filter_model_converter * fmc = alloc(filter_model_converter, m());
-                            for (unsigned i = 0; i < fresh_vars.size(); i++)
-                                fmc->insert(fresh_vars.get(i)->get_decl());
+                            generic_model_converter * fmc = alloc(generic_model_converter, m());
+                            for (app * f : fresh_vars) 
+                                fmc->hide(f);
                             mc = concat(fmc, m_mc.get());
                         }
                         else {
@@ -910,7 +909,7 @@ class elim_uncnstr_tactic : public tactic {
     imp *      m_imp;
     params_ref m_params;
 public:
-    elim_uncnstr_tactic(ast_manager & m, params_ref const & p):
+   elim_uncnstr_tactic(ast_manager & m, params_ref const & p):
         m_params(p) {
         m_imp = alloc(imp, m, p);
     }
diff --git a/src/tactic/core/nnf_tactic.cpp b/src/tactic/core/nnf_tactic.cpp
index 6b360e711..9750ad29c 100644
--- a/src/tactic/core/nnf_tactic.cpp
+++ b/src/tactic/core/nnf_tactic.cpp
@@ -18,7 +18,7 @@ Revision History:
 --*/
 #include "ast/normal_forms/nnf.h"
 #include "tactic/tactical.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 
 class nnf_tactic : public tactic {
     params_ref    m_params;
@@ -97,10 +97,10 @@ public:
         result.push_back(g.get());
         unsigned num_extra_names = dnames.get_num_names();
         if (num_extra_names > 0) {
-            filter_model_converter * fmc = alloc(filter_model_converter, m);
+            generic_model_converter * fmc = alloc(generic_model_converter, m);
             mc = fmc;
             for (unsigned i = 0; i < num_extra_names; i++)
-                fmc->insert(dnames.get_name_decl(i));
+                fmc->hide(dnames.get_name_decl(i));
         }
         TRACE("nnf", g->display(tout););
         SASSERT(g->is_well_sorted());
diff --git a/src/tactic/core/occf_tactic.cpp b/src/tactic/core/occf_tactic.cpp
index 6d9d63971..66143b6b5 100644
--- a/src/tactic/core/occf_tactic.cpp
+++ b/src/tactic/core/occf_tactic.cpp
@@ -23,13 +23,13 @@ Revision History:
 --*/
 #include "tactic/tactical.h"
 #include "tactic/core/occf_tactic.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "util/cooperate.h"
 
 class occf_tactic : public tactic {
     struct     imp {
         ast_manager &            m;
-        filter_model_converter * m_mc;
+        generic_model_converter * m_mc;
         
         imp(ast_manager & _m):
             m(_m) {
@@ -115,7 +115,7 @@ class occf_tactic : public tactic {
             SASSERT(!c2b.contains(cnstr));
             expr * bvar = m.mk_fresh_const(0, m.mk_bool_sort());
             if (produce_models)
-                m_mc->insert(to_app(bvar)->get_decl());
+                m_mc->hide(to_app(bvar)->get_decl());
             c2b.insert(cnstr, bvar_info(bvar, sign));
             if (sign) {
                 g->assert_expr(m.mk_or(bvar, m.mk_not(cnstr)), 0, 0);
@@ -157,7 +157,7 @@ class occf_tactic : public tactic {
                 if (!is_target(cls))
                     continue;
                 if (produce_models && !m_mc) {
-                    m_mc = alloc(filter_model_converter, m);
+                    m_mc = alloc(generic_model_converter, m);
                     mc = m_mc;
                 }
                 expr * keep = 0;
diff --git a/src/tactic/core/reduce_args_tactic.cpp b/src/tactic/core/reduce_args_tactic.cpp
index 476c21232..aaf85eacd 100644
--- a/src/tactic/core/reduce_args_tactic.cpp
+++ b/src/tactic/core/reduce_args_tactic.cpp
@@ -23,7 +23,7 @@ Notes:
 #include "util/map.h"
 #include "ast/rewriter/rewriter_def.h"
 #include "tactic/extension_model_converter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 
 /**
    \brief Reduce the number of arguments in function applications.
@@ -395,7 +395,7 @@ struct reduce_args_tactic::imp {
         var_ref_vector   new_vars(m_manager);
         ptr_buffer<expr> new_eqs;
         extension_model_converter * e_mc = alloc(extension_model_converter, m_manager);
-        filter_model_converter * f_mc    = alloc(filter_model_converter, m_manager);
+        generic_model_converter * f_mc    = alloc(generic_model_converter, m_manager);
         decl2arg2func_map::iterator it   = decl2arg2funcs.begin();
         decl2arg2func_map::iterator end  = decl2arg2funcs.end();
         for (; it != end; ++it) {
@@ -416,7 +416,7 @@ struct reduce_args_tactic::imp {
             for (; it2 != end2; ++it2) {
                 app * t = it2->m_key;
                 func_decl * new_def = it2->m_value;
-                f_mc->insert(new_def);
+                f_mc->hide(new_def);
                 SASSERT(new_def->get_arity() == new_args.size());
                 app * new_t = m_manager.mk_app(new_def, new_args.size(), new_args.c_ptr());
                 if (def == 0) {
diff --git a/src/tactic/core/tseitin_cnf_tactic.cpp b/src/tactic/core/tseitin_cnf_tactic.cpp
index dbfc748b0..4791b5ce6 100644
--- a/src/tactic/core/tseitin_cnf_tactic.cpp
+++ b/src/tactic/core/tseitin_cnf_tactic.cpp
@@ -51,7 +51,7 @@ Notes:
 --*/
 #include "tactic/tactical.h"
 #include "tactic/goal_shared_occs.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/rewriter/bool_rewriter.h"
 #include "tactic/core/simplify_tactic.h"
 #include "util/cooperate.h"
@@ -80,7 +80,7 @@ class tseitin_cnf_tactic : public tactic {
             frame(app * n):m_t(n), m_first(true) {}
         };
         
-        typedef filter_model_converter mc;
+        typedef generic_model_converter mc;
         
         ast_manager &              m;
         svector<frame>             m_frame_stack;
@@ -344,7 +344,7 @@ class tseitin_cnf_tactic : public tactic {
             app * v = m.mk_fresh_const(0, m.mk_bool_sort());
             m_fresh_vars.push_back(v);
             if (m_mc)
-                m_mc->insert(v->get_decl());
+                m_mc->hide(v->get_decl());
             return v;
         }
         
@@ -817,7 +817,7 @@ class tseitin_cnf_tactic : public tactic {
             m_frame_stack.reset();
             m_clauses.reset();
             if (m_produce_models)
-                m_mc = alloc(filter_model_converter, m);
+                m_mc = alloc(generic_model_converter, m);
             else
                 m_mc = 0;
 
diff --git a/src/tactic/extension_model_converter.h b/src/tactic/extension_model_converter.h
index 7ee6c68f5..26f1611ef 100644
--- a/src/tactic/extension_model_converter.h
+++ b/src/tactic/extension_model_converter.h
@@ -10,6 +10,8 @@ Abstract:
     Model converter that introduces new interpretations into a model.
     It used to be called elim_var_model_converter
 
+    TBD: special case of generic_model_converter
+
 Author:
 
     Leonardo (leonardo) 2011-10-21
diff --git a/src/tactic/filter_model_converter.cpp b/src/tactic/filter_model_converter.cpp
deleted file mode 100644
index 7400063e1..000000000
--- a/src/tactic/filter_model_converter.cpp
+++ /dev/null
@@ -1,74 +0,0 @@
-/*++
-Copyright (c) 2011 Microsoft Corporation
-
-Module Name:
-
-    filter_model_converter.cpp
-
-Abstract:
-
-    Filter decls from a model
-
-Author:
-
-    Leonardo (leonardo) 2011-05-06
-
-Notes:
-
---*/
-#include "tactic/filter_model_converter.h"
-#include "model/model_v2_pp.h"
-
-filter_model_converter::~filter_model_converter() {
-}
-
-void filter_model_converter::operator()(model_ref & old_model, unsigned goal_idx) {
-    TRACE("filter_mc", tout << "before filter_model_converter\n"; model_v2_pp(tout, *old_model); display(tout););
-    ast_fast_mark1 fs;
-    unsigned num = m_decls.size();
-    for (unsigned i = 0; i < num; i++) 
-        fs.mark(m_decls.get(i));
-    model * new_model = alloc(model, m());
-    num = old_model->get_num_constants();
-    for (unsigned i = 0; i < num; i++) {
-        func_decl * f = old_model->get_constant(i);
-        if (fs.is_marked(f))
-            continue;
-        expr * fi     = old_model->get_const_interp(f);
-        new_model->register_decl(f, fi);
-    }
-    num = old_model->get_num_functions();
-    for (unsigned i = 0; i < num; i++) {
-        func_decl * f = old_model->get_function(i);
-        if (fs.is_marked(f))
-            continue;
-        func_interp * fi = old_model->get_func_interp(f);
-        SASSERT(fi);
-        new_model->register_decl(f, fi->copy());
-    }
-    new_model->copy_usort_interps(*old_model);
-    old_model = new_model;
-    TRACE("filter_mc", tout << "after filter_model_converter\n"; model_v2_pp(tout, *old_model););
-}
-
-void filter_model_converter::operator()(svector<symbol> & labels, unsigned goal_idx) {
-}
-
-void filter_model_converter::display(std::ostream & out) {
-    for (func_decl* f : m_decls) {
-        display_del(out, f);
-    }
-}
-
-model_converter * filter_model_converter::translate(ast_translation & translator) {
-    filter_model_converter * res = alloc(filter_model_converter, translator.to());
-    for (func_decl* f : m_decls) 
-        res->m_decls.push_back(translator(f));
-    return res;
-}
-
-void filter_model_converter::collect(ast_pp_util& visitor) { 
-    m_env = &visitor.env(); 
-    for (func_decl* f : m_decls) visitor.coll.visit_func(f);
-}
-
diff --git a/src/tactic/filter_model_converter.h b/src/tactic/filter_model_converter.h
deleted file mode 100644
index 2c3361808..000000000
--- a/src/tactic/filter_model_converter.h
+++ /dev/null
@@ -1,56 +0,0 @@
-/*++
-Copyright (c) 2011 Microsoft Corporation
-
-Module Name:
-
-    filter_model_converter.h
-
-Abstract:
-
-    Filter decls from a model
-
-Author:
-
-    Leonardo (leonardo) 2011-05-06
-
-Notes:
-
---*/
-#ifndef FILTER_MODEL_CONVERTER_H_
-#define FILTER_MODEL_CONVERTER_H_
-
-#include "tactic/model_converter.h"
-#include "ast/ast_pp_util.h"
-
-class filter_model_converter : public model_converter {
-    func_decl_ref_vector  m_decls;
-public:
-    filter_model_converter(ast_manager & m): m_decls(m) {}
-    
-    virtual ~filter_model_converter();
-    
-    ast_manager & m() const { return m_decls.get_manager(); }
-    
-    virtual void operator()(model_ref & md, unsigned goal_idx);
-
-    virtual void operator()(svector<symbol> & labels, unsigned goal_idx);
-    
-    virtual void operator()(model_ref & md) { operator()(md, 0); } // TODO: delete
-
-    virtual void cancel() {}
-    
-    virtual void display(std::ostream & out);
-
-    void insert(func_decl * d) {
-        m_decls.push_back(d);
-    }
-
-    virtual model_converter * translate(ast_translation & translator);
-
-    virtual void collect(ast_pp_util& visitor);
-
-};
-
-typedef ref<filter_model_converter> filter_model_converter_ref;
-
-#endif
diff --git a/src/tactic/generic_model_converter.cpp b/src/tactic/generic_model_converter.cpp
index f8a701003..629004869 100644
--- a/src/tactic/generic_model_converter.cpp
+++ b/src/tactic/generic_model_converter.cpp
@@ -85,3 +85,7 @@ void generic_model_converter::collect(ast_pp_util& visitor) {
         if (e.m_def) visitor.coll.visit(e.m_def);
     }
 }
+
+void generic_model_converter::operator()(expr_ref& fml) {
+    NOT_IMPLEMENTED_YET();
+}
diff --git a/src/tactic/generic_model_converter.h b/src/tactic/generic_model_converter.h
index 434514ce6..c58d0d029 100644
--- a/src/tactic/generic_model_converter.h
+++ b/src/tactic/generic_model_converter.h
@@ -38,6 +38,8 @@ public:
     
     virtual ~generic_model_converter() { }
     
+    void hide(expr* e) { SASSERT(is_app(e) && to_app(e)->get_num_args() == 0); hide(to_app(e)->get_decl()); }
+
     void hide(func_decl * f) { m_entries.push_back(entry(f, 0, m, HIDE)); }
 
     void add(func_decl * d, expr* e) { m_entries.push_back(entry(d, e, m, ADD)); }
@@ -55,6 +57,8 @@ public:
     virtual model_converter * translate(ast_translation & translator);
 
     virtual void collect(ast_pp_util& visitor);
+
+    void operator()(expr_ref& fml) override; 
 };
 
 typedef ref<generic_model_converter> generic_model_converter_ref;
diff --git a/src/tactic/model_converter.h b/src/tactic/model_converter.h
index f7597be07..720ae1916 100644
--- a/src/tactic/model_converter.h
+++ b/src/tactic/model_converter.h
@@ -45,12 +45,19 @@ public:
         SASSERT(goal_idx == 0);
         operator()(m);
     }
-    virtual void operator()(labels_vec & r, unsigned goal_idx) {}
 
+    virtual void operator()(labels_vec & r, unsigned goal_idx) {}
     
     virtual model_converter * translate(ast_translation & translator) = 0;
     
     virtual void collect(ast_pp_util& visitor) { m_env = &visitor.env(); }
+
+    /**
+       \brief we are adding a formula to the context of the model converter.
+       The operator has as side effect of adding definitions as assertions to the
+       formula and removing these definitions from the model converter.
+     */
+    virtual void operator()(expr_ref& formula) { UNREACHABLE(); }
 };
 
 typedef ref<model_converter> model_converter_ref;
diff --git a/src/tactic/nlsat_smt/nl_purify_tactic.cpp b/src/tactic/nlsat_smt/nl_purify_tactic.cpp
index c99ea545a..e389c960c 100644
--- a/src/tactic/nlsat_smt/nl_purify_tactic.cpp
+++ b/src/tactic/nlsat_smt/nl_purify_tactic.cpp
@@ -49,7 +49,7 @@ Revision History:
 #include "smt/tactic/smt_tactic.h"
 #include "ast/rewriter/rewriter.h"
 #include "nlsat/tactic/nlsat_tactic.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "util/obj_pair_hashtable.h"
 #include "ast/rewriter/rewriter_def.h"
 #include "ast/ast_pp.h"
@@ -73,7 +73,7 @@ class nl_purify_tactic : public tactic {
     arith_util      m_util;
     params_ref      m_params;
     bool            m_produce_proofs;
-    ref<filter_model_converter> m_fmc;
+    ref<generic_model_converter> m_fmc;
     tactic_ref      m_nl_tac;       // nlsat tactic
     goal_ref        m_nl_g;         // nlsat goal
     ref<solver>     m_solver;       // SMT solver
@@ -133,7 +133,7 @@ public:
             }
             r = m.mk_fresh_const(0, u().mk_real());
             m_new_reals.push_back(to_app(r));
-            m_owner.m_fmc->insert(to_app(r)->get_decl());
+            m_owner.m_fmc->hide(r);
             m_interface_cache.insert(arg, r);
             expr_ref eq(m);
             eq = m.mk_eq(r, arg);
@@ -159,7 +159,7 @@ public:
             result = m.mk_fresh_const(0, m.mk_bool_sort());
             m_polarities.insert(result, pol);
             m_new_preds.push_back(to_app(result));
-            m_owner.m_fmc->insert(to_app(result)->get_decl());
+            m_owner.m_fmc->hide(result);
             if (pol != pol_neg) {
                 m_owner.m_nl_g->assert_expr(m.mk_or(m.mk_not(result), old_pred));
             }
@@ -491,7 +491,7 @@ private:
                     pred = m.mk_fresh_const(0, m.mk_bool_sort());
                     m_eq_preds.push_back(pred);
                     m_eq_values.push_back(l_true);
-                    m_fmc->insert(to_app(pred)->get_decl());
+                    m_fmc->hide(pred);
                     nl_g->assert_expr(m.mk_or(m.mk_not(pred), m.mk_eq(w, v)));
                     nl_g->assert_expr(m.mk_or(pred, m.mk_not(m.mk_eq(w, v))));
                     m_solver->assert_expr(m.mk_iff(pred, m.mk_eq(w, v)));
@@ -761,7 +761,7 @@ public:
         rw r(*this);
         expr_ref_vector clauses(m);
         m_nl_g = alloc(goal, m, true, false);
-        m_fmc = alloc(filter_model_converter, m);                
+        m_fmc = alloc(generic_model_converter, m);                
 
         // first hoist interface variables, 
         // then annotate subformulas by polarities,
diff --git a/src/tactic/portfolio/bounded_int2bv_solver.cpp b/src/tactic/portfolio/bounded_int2bv_solver.cpp
index c0e5e0a46..ef8012dd9 100644
--- a/src/tactic/portfolio/bounded_int2bv_solver.cpp
+++ b/src/tactic/portfolio/bounded_int2bv_solver.cpp
@@ -21,7 +21,7 @@ Notes:
 #include "solver/solver_na2as.h"
 #include "tactic/tactic.h"
 #include "ast/rewriter/pb2bv_rewriter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "tactic/extension_model_converter.h"
 #include "ast/ast_pp.h"
 #include "model/model_smt2_pp.h"
@@ -86,7 +86,7 @@ public:
         return result;
     }
 
-    virtual void assert_expr(expr * t) {
+    virtual void assert_expr_core(expr * t) {
         unsigned i = m_assertions.size();
         m_assertions.push_back(t);
         while (i < m_assertions.size()) {
@@ -209,10 +209,8 @@ private:
         if (m_bv_fns.empty()) {
             return;
         }
-        filter_model_converter filter(m);
-        for (unsigned i = 0; i < m_bv_fns.size(); ++i) {
-            filter.insert(m_bv_fns[i].get());
-        }
+        generic_model_converter filter(m);
+        for (func_decl* f : m_bv_fns) filter.hide(f);
         filter(mdl, 0);
     }
 
diff --git a/src/tactic/portfolio/enum2bv_solver.cpp b/src/tactic/portfolio/enum2bv_solver.cpp
index 4722f9289..19b5374ac 100644
--- a/src/tactic/portfolio/enum2bv_solver.cpp
+++ b/src/tactic/portfolio/enum2bv_solver.cpp
@@ -26,7 +26,7 @@ Notes:
 #include "model/model_smt2_pp.h"
 #include "tactic/tactic.h"
 #include "tactic/extension_model_converter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "tactic/portfolio/enum2bv_solver.h"
 #include "solver/solver_na2as.h"
 #include "ast/rewriter/enum2bv_rewriter.h"
@@ -58,7 +58,7 @@ public:
         return result;
     }
     
-    virtual void assert_expr(expr * t) {
+    virtual void assert_expr_core(expr * t) {
         expr_ref tmp(t, m);
         expr_ref_vector bounds(m);
         proof_ref tmp_proof(m);
@@ -164,9 +164,9 @@ public:
     }
 
     void filter_model(model_ref& mdl) {
-        filter_model_converter filter(m);
+        generic_model_converter filter(m);
         for (auto const& kv : m_rewriter.enum2bv()) {
-            filter.insert(kv.m_value);
+            filter.hide(kv.m_value);
         }
         filter(mdl, 0);
     }
diff --git a/src/tactic/portfolio/parallel_tactic.cpp b/src/tactic/portfolio/parallel_tactic.cpp
index 8a6c6fa15..e9c6d76aa 100644
--- a/src/tactic/portfolio/parallel_tactic.cpp
+++ b/src/tactic/portfolio/parallel_tactic.cpp
@@ -549,7 +549,7 @@ public:
         expr_ref_vector clauses(m);
         ptr_vector<expr> assumptions;
         obj_map<expr, expr*> bool2dep;
-        ref<filter_model_converter> fmc;
+        ref<generic_model_converter> fmc;
         extract_clauses_and_dependencies(g, clauses, assumptions, bool2dep, fmc);
         for (expr * clause : clauses) {
             s->assert_expr(clause);
diff --git a/src/tactic/portfolio/pb2bv_solver.cpp b/src/tactic/portfolio/pb2bv_solver.cpp
index f6a7b1622..334d14d86 100644
--- a/src/tactic/portfolio/pb2bv_solver.cpp
+++ b/src/tactic/portfolio/pb2bv_solver.cpp
@@ -21,7 +21,7 @@ Notes:
 #include "tactic/tactic.h"
 #include "ast/rewriter/pb2bv_rewriter.h"
 #include "ast/rewriter/th_rewriter.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/ast_pp.h"
 #include "model/model_smt2_pp.h"
 
@@ -57,7 +57,7 @@ public:
         return result;
     }
     
-    virtual void assert_expr(expr * t) {
+    virtual void assert_expr_core(expr * t) {
         m_assertions.push_back(t);
     }
 
@@ -113,10 +113,10 @@ public:
         if (m_rewriter.fresh_constants().empty()) {
             return;
         }
-        filter_model_converter filter(m);
+        generic_model_converter filter(m);
         func_decl_ref_vector const& fns = m_rewriter.fresh_constants();
-        for (unsigned i = 0; i < fns.size(); ++i) {
-            filter.insert(fns[i]);
+        for (func_decl* f : fns) {
+            filter.hide(f);
         }
         filter(mdl, 0);
     }
@@ -138,8 +138,8 @@ private:
         proof_ref proof(m);
         expr_ref fml1(m), fml(m);
         expr_ref_vector fmls(m);
-        for (unsigned i = 0; i < m_assertions.size(); ++i) {
-            m_th_rewriter(m_assertions[i].get(), fml1, proof);
+        for (expr* a : m_assertions) {
+            m_th_rewriter(a, fml1, proof);
             m_rewriter(fml1, fml, proof);
             m_solver->assert_expr(fml);
         }
diff --git a/src/tactic/sine_filter.cpp b/src/tactic/sine_filter.cpp
index ba35bac84..1e0eabac6 100644
--- a/src/tactic/sine_filter.cpp
+++ b/src/tactic/sine_filter.cpp
@@ -18,10 +18,9 @@ Revision History:
 
 #include "tactic/sine_filter.h"
 #include "tactic/tactical.h"
-#include "tactic/filter_model_converter.h"
+#include "tactic/generic_model_converter.h"
 #include "ast/datatype_decl_plugin.h"
 #include "ast/rewriter/rewriter_def.h"
-#include "tactic/filter_model_converter.h"
 #include "tactic/extension_model_converter.h"
 #include "ast/rewriter/var_subst.h"
 #include "ast/ast_util.h"
@@ -69,7 +68,7 @@ public:
         result.push_back(g.get());
         TRACE("sine", result[0]->display(tout););
         SASSERT(g->is_well_sorted());
-        filter_model_converter * fmc = alloc(filter_model_converter, m);
+        generic_model_converter * fmc = alloc(generic_model_converter, m);
         mc = fmc;
     }