diff --git a/src/opt/fu_malik.cpp b/src/opt/fu_malik.cpp
index 306b3e579..d6e435be9 100644
--- a/src/opt/fu_malik.cpp
+++ b/src/opt/fu_malik.cpp
@@ -132,6 +132,8 @@ namespace opt {
         }
 
     };
+
+    // TBD: bug when cancel flag is set, fu_malik returns is_sat == l_true instead of l_undef
     
     lbool fu_malik_maxsat(solver& s, expr_ref_vector& soft_constraints) {
         ast_manager& m = soft_constraints.get_manager();
diff --git a/src/opt/opt_context.cpp b/src/opt/opt_context.cpp
index fbc2981ca..ed971506d 100644
--- a/src/opt/opt_context.cpp
+++ b/src/opt/opt_context.cpp
@@ -21,8 +21,6 @@ Notes:
 --*/
 
 #include "opt_context.h"
-#include "fu_malik.h"
-#include "weighted_maxsat.h"
 #include "ast_pp.h"
 #include "opt_solver.h"
 #include "arith_decl_plugin.h"
@@ -37,7 +35,8 @@ namespace opt {
         m_hard_constraints(m),
         m_soft_constraints(m),
         m_objectives(m),
-        m_opt_objectives(m)
+        m_opt_objectives(m),
+        m_maxsmt(m)
     {
         m_params.set_bool("model", true);
         m_params.set_bool("unsat_core", true);
@@ -45,57 +44,30 @@ namespace opt {
 
     void context::optimize() {
 
-        expr_ref_vector const& fmls = m_soft_constraints;
-
         if (!m_solver) {
             symbol logic;
             set_solver(alloc(opt_solver, m, m_params, logic));
         }
-        solver* s = m_solver.get();
+
+        // really just works for opt_solver now.
+        solver* s = m_solver.get(); 
+        opt_solver::scoped_push _sp(get_opt_solver(*s));
 
         for (unsigned i = 0; i < m_hard_constraints.size(); ++i) {
             s->assert_expr(m_hard_constraints[i].get());
         }
-
-        expr_ref_vector fmls_copy(fmls);
+        
         lbool is_sat;
-        if (!fmls.empty()) {
-            // TBD: bug when cancel flag is set, fu_malik returns is_sat == l_true instead of l_undef
-            if (is_maxsat_problem()) {
-                is_sat = opt::fu_malik_maxsat(*s, fmls_copy);
-            }
-            else {
-                is_sat = weighted_maxsat(get_opt_solver(*s), fmls_copy, m_weights);
-            }
-            std::cout << "is-sat: " << is_sat << "\n";
-            if (is_sat != l_true) {
-                return;
-            }
-            std::cout << "Satisfying soft constraints\n";
-            for (unsigned i = 0; i < fmls_copy.size(); ++i) {
-                std::cout << mk_pp(fmls_copy[i].get(), m) << "\n";
-            }            
+
+        is_sat = m_maxsmt(get_opt_solver(*s), m_soft_constraints, m_weights);
+
+        for (unsigned i = 0; i < m_soft_constraints.size(); ++i) {
+            s->assert_expr(m_soft_constraints[i].get());
         }
 
-        if (!m_objectives.empty()) {
-            vector<inf_eps_rational<inf_rational> > values;
-            for (unsigned i = 0; i < fmls_copy.size(); ++i) {
-                s->assert_expr(fmls_copy[i].get());
-            }
-            is_sat = m_opt_objectives(get_opt_solver(*s), m_objectives, values);
-            std::cout << "is-sat: " << is_sat << std::endl;
-
-            if (is_sat != l_true) {
-                return;
-            }
-
-            for (unsigned i = 0; i < values.size(); ++i) {
-                if (!m_is_max[i]) {
-                    values[i].neg();
-                }
-                std::cout << "objective value: " << mk_pp(m_objectives[i].get(), m) << " -> " << values[i].to_string() << std::endl;                
-            }
-        }     
+        if (is_sat == l_true) {           
+            is_sat = m_opt_objectives(get_opt_solver(*s), m_objectives);        
+        }
 
         if (m_objectives.empty() && m_soft_constraints.empty()) {
             is_sat = s->check_sat(0,0);
@@ -103,15 +75,6 @@ namespace opt {
         }
     }
         
-    bool context::is_maxsat_problem() const {
-        vector<rational> const& ws  = m_weights;
-        for (unsigned i = 0; i < ws.size(); ++i) {
-            if (!ws[i].is_one()) {
-                return false;
-            }
-        }
-        return true;
-    }
 
     opt_solver& context::get_opt_solver(solver& s) {
         if (typeid(opt_solver) != typeid(s)) {
@@ -125,6 +88,7 @@ namespace opt {
             m_solver->cancel();
         }
         m_opt_objectives.set_cancel(true);
+        m_maxsmt.set_cancel(true);
     }
 
     void context::reset_cancel() {
@@ -132,6 +96,7 @@ namespace opt {
             m_solver->reset_cancel();
         }
         m_opt_objectives.set_cancel(false);
+        m_maxsmt.set_cancel(false);
     }
 
     void context::add_objective(app* t, bool is_max) {
diff --git a/src/opt/opt_context.h b/src/opt/opt_context.h
index 0aa137748..6a12fa8d6 100644
--- a/src/opt/opt_context.h
+++ b/src/opt/opt_context.h
@@ -28,6 +28,7 @@ Notes:
 #include "ast.h"
 #include "solver.h"
 #include "optimize_objectives.h"
+#include "opt_maxsmt.h"
 
 namespace opt {
 
@@ -43,6 +44,7 @@ namespace opt {
         ref<solver>      m_solver;
         params_ref       m_params;
         optimize_objectives m_opt_objectives;
+        maxsmt           m_maxsmt;
     public:
         context(ast_manager& m);
 
diff --git a/src/opt/opt_maxsmt.cpp b/src/opt/opt_maxsmt.cpp
new file mode 100644
index 000000000..14095252b
--- /dev/null
+++ b/src/opt/opt_maxsmt.cpp
@@ -0,0 +1,66 @@
+/*++
+Copyright (c) 2013 Microsoft Corporation
+
+Module Name:
+
+    opt_maxsmt.cpp
+
+Abstract:
+   
+    MaxSMT optimization context.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2013-11-7
+
+Notes:
+
+--*/
+
+#include "opt_maxsmt.h"
+#include "fu_malik.h"
+#include "weighted_maxsat.h"
+#include "ast_pp.h"
+
+namespace opt {
+
+    lbool maxsmt::operator()(opt_solver& s, expr_ref_vector& fmls, vector<rational> const& ws) {
+        lbool is_sat;
+        
+        if (fmls.empty()) {
+            is_sat = s.check_sat(0, 0);
+        }
+        else if (is_maxsat_problem(ws)) {
+            is_sat = opt::fu_malik_maxsat(s, fmls);
+        }
+        else {
+            is_sat = weighted_maxsat(s, fmls, ws);
+        }
+
+        // Infrastructure for displaying and storing solution is TBD.
+        std::cout << "is-sat: " << is_sat << "\n";
+        if (is_sat == l_true) {
+            std::cout << "Satisfying soft constraints\n";
+            for (unsigned i = 0; i < fmls.size(); ++i) {
+                std::cout << mk_pp(fmls[i].get(), m) << "\n";
+            }           
+        } 
+        return is_sat;
+    }
+    
+    void maxsmt::set_cancel(bool f) {
+        m_cancel = f;
+    }
+    
+    bool maxsmt::is_maxsat_problem(vector<rational> const& ws) const {
+        for (unsigned i = 0; i < ws.size(); ++i) {
+            if (!ws[i].is_one()) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+
+
+};
diff --git a/src/opt/opt_maxsmt.h b/src/opt/opt_maxsmt.h
new file mode 100644
index 000000000..d674ff692
--- /dev/null
+++ b/src/opt/opt_maxsmt.h
@@ -0,0 +1,52 @@
+/*++
+Copyright (c) 2013 Microsoft Corporation
+
+Module Name:
+
+    opt_maxsmt.h
+
+Abstract:
+   
+    MaxSMT optimization context.
+
+Author:
+
+    Nikolaj Bjorner (nbjorner) 2013-11-7
+
+Notes:
+
+--*/
+#ifndef _OPT_MAXSMT_H_
+#define _OPT_MAXSMT_H_
+
+#include "opt_solver.h"
+
+namespace opt {
+    /**
+       Takes solver with hard constraints added.
+       Returns modified soft constraints that are maximal assignments.
+    */
+
+    class maxsmt {
+        ast_manager&  m;
+        opt_solver*   s;
+        volatile bool m_cancel;
+        symbol        m_engine;
+    public:
+        maxsmt(ast_manager& m): m(m), s(0), m_cancel(false) {}
+
+        lbool operator()(opt_solver& s, expr_ref_vector& soft, vector<rational> const& weights);
+
+        void set_cancel(bool f);
+
+        void set_engine(symbol const& e) { m_engine = e; }
+
+    private:
+
+        bool is_maxsat_problem(vector<rational> const& ws) const;        
+
+    };
+
+};
+
+#endif
diff --git a/src/opt/optimize_objectives.cpp b/src/opt/optimize_objectives.cpp
index 9705652fb..ad921934e 100644
--- a/src/opt/optimize_objectives.cpp
+++ b/src/opt/optimize_objectives.cpp
@@ -204,23 +204,25 @@ namespace opt {
        Takes solver with hard constraints added.
        Returns an optimal assignment to objective functions.
     */
-    lbool optimize_objectives::operator()(opt_solver& solver, app_ref_vector& objectives, vector<inf_eps>& values) {
+    lbool optimize_objectives::operator()(opt_solver& solver, app_ref_vector const& objectives) {
         s = &solver;
         s->reset_objectives();
         m_lower.reset();
         m_upper.reset();
+        m_objs.reset();
         for (unsigned i = 0; i < objectives.size(); ++i) {
             m_lower.push_back(inf_eps(rational(-1),inf_rational(0)));
             m_upper.push_back(inf_eps(rational(1), inf_rational(0)));
+            m_objs.push_back(objectives[i]);
         }
 
         // First check_sat call to initialize theories
         lbool is_sat = s->check_sat(0, 0);
-        if (is_sat == l_true) {
+        if (is_sat == l_true && !objectives.empty()) {
             opt_solver::scoped_push _push(*s);
             
             for (unsigned i = 0; i < objectives.size(); ++i) {
-                m_vars.push_back(s->add_objective(objectives[i].get()));
+                m_vars.push_back(s->add_objective(objectives[i]));
             }
 
             if (m_engine == symbol("basic")) {
@@ -235,12 +237,31 @@ namespace opt {
                 NOT_IMPLEMENTED_YET();
                 UNREACHABLE();
             }
-            values.reset();
-            values.append(m_lower);
         }
+
+        std::cout << "is-sat: " << is_sat << std::endl;
+        display(std::cout);
+
         return is_sat;
     }
 
+    inf_eps  optimize_objectives::get_value(bool as_positive, unsigned index) const {
+        if (as_positive) {
+            return m_lower[index];
+        }
+        else {
+            return -m_lower[index];
+        }
+    }
+
+    void optimize_objectives::display(std::ostream& out) const {
+        unsigned sz = m_objs.size();
+        for (unsigned i = 0; i < sz; ++i) {
+            out << "objective value: " << mk_pp(m_objs[i], m) << " -> " << get_value(true, i).to_string() << std::endl;                
+        }        
+    }
+
+
 }
 
 #endif
diff --git a/src/opt/optimize_objectives.h b/src/opt/optimize_objectives.h
index cb9f2241b..c9f5ffc55 100644
--- a/src/opt/optimize_objectives.h
+++ b/src/opt/optimize_objectives.h
@@ -33,17 +33,22 @@ namespace opt {
         volatile bool m_cancel;
         vector<inf_eps> m_lower;
         vector<inf_eps> m_upper;
+        app_ref_vector  m_objs;
         svector<smt::theory_var> m_vars;
         symbol m_engine;
     public:
-        optimize_objectives(ast_manager& m): m(m), s(0), m_cancel(false) {}
+        optimize_objectives(ast_manager& m): m(m), s(0), m_cancel(false), m_objs(m) {}
 
-        lbool operator()(opt_solver& s, app_ref_vector& objectives, vector<inf_eps>& values);
+        lbool operator()(opt_solver& s, app_ref_vector const& objectives);
 
         void set_cancel(bool f);
 
         void set_engine(symbol const& e) { m_engine = e; }
 
+        void display(std::ostream& out) const;
+
+        inf_eps get_value(bool as_positive, unsigned index) const;
+
     private:
         
         lbool basic_opt();
diff --git a/src/smt/theory_card.cpp b/src/smt/theory_card.cpp
index ebcd52d56..4cd23d225 100644
--- a/src/smt/theory_card.cpp
+++ b/src/smt/theory_card.cpp
@@ -66,10 +66,13 @@ namespace smt {
         SASSERT(m_util.is_at_most_k(atom));
         unsigned k = m_util.get_k(atom);
 
+
         if (ctx.b_internalized(atom)) {
             return false;
         }
 
+        m_stats.m_num_predicates++;
+
         TRACE("card", tout << "internalize: " << mk_pp(atom, m) << "\n";);
 
         SASSERT(!ctx.b_internalized(atom));
@@ -210,7 +213,10 @@ namespace smt {
         m_cards_trail.push_back(abv);
     }
 
-    
+    void theory_card::collect_statistics(::statistics& st) const {
+        st.update("pb axioms", m_stats.m_num_axioms);
+        st.update("pb predicates", m_stats.m_num_predicates);        
+    }
     
     void theory_card::reset_eh() {
         
@@ -229,6 +235,7 @@ namespace smt {
         m_cards_lim.reset();
         m_watch_trail.reset();
         m_watch_lim.reset();
+        m_stats.reset();
     }
 
     void theory_card::update_min_max(bool_var v, bool is_true, card* c) {
@@ -470,8 +477,16 @@ namespace smt {
     }
 
     void theory_card::add_clause(literal_vector const& lits) {
+        m_stats.m_num_axioms++;
         context& ctx = get_context();
         TRACE("card", ctx.display_literals_verbose(tout, lits.size(), lits.c_ptr()); tout << "\n";);
-        ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
+        justification* js = 0;
+        ctx.mk_clause(lits.size(), lits.c_ptr(), js, CLS_AUX_LEMMA, 0);
+        IF_VERBOSE(0, 
+                   for (unsigned i = 0; i < lits.size(); ++i) {
+                       verbose_stream() << lits[i] << " ";
+                   }
+                   verbose_stream() << "\n";);
+        // ctx.mk_th_axiom(get_id(), lits.size(), lits.c_ptr());
     }
 }
diff --git a/src/smt/theory_card.h b/src/smt/theory_card.h
index c53e38e37..3c9e3c1f9 100644
--- a/src/smt/theory_card.h
+++ b/src/smt/theory_card.h
@@ -28,6 +28,13 @@ namespace smt {
 
         typedef svector<std::pair<bool_var, int> > arg_t;
 
+        struct stats {
+            unsigned m_num_axioms;
+            unsigned m_num_predicates;
+            void reset() { memset(this, 0, sizeof(*this)); }
+            stats() { reset(); }
+        };
+
         struct card {
             int      m_k;
             bool_var m_bv;
@@ -49,6 +56,7 @@ namespace smt {
         unsigned_vector          m_watch_lim;
         literal_vector           m_literals;
         card_util                m_util;
+        stats                    m_stats;
 
         void add_watch(bool_var bv, card* c);
         void add_card(card* c);
@@ -84,6 +92,7 @@ namespace smt {
         virtual void init_search_eh();
         virtual void push_scope_eh();
         virtual void pop_scope_eh(unsigned num_scopes);
+        virtual void collect_statistics(::statistics & st) const;
 
     };
 };
diff --git a/src/tactic/arith/lia2card_tactic.cpp b/src/tactic/arith/lia2card_tactic.cpp
index d2be433c6..5130eea9d 100644
--- a/src/tactic/arith/lia2card_tactic.cpp
+++ b/src/tactic/arith/lia2card_tactic.cpp
@@ -92,6 +92,7 @@ class lia2card_tactic : public tactic {
             it = m_01s.begin(), end = m_01s.end();
             for (; it != end; ++it) {
                 if (!validate_uses(m_uses.find(*it))) {
+                    std::cout << "did not validate: " << mk_pp(*it, m) << "\n";
                     m_uses.remove(*it);
                     m_01s.remove(*it);
                     it = m_01s.begin();