diff --git a/src/ast/recfun_decl_plugin.cpp b/src/ast/recfun_decl_plugin.cpp
index 86c3fcf3b..84d68d782 100644
--- a/src/ast/recfun_decl_plugin.cpp
+++ b/src/ast/recfun_decl_plugin.cpp
@@ -36,7 +36,6 @@ namespace recfun {
         ast_manager &m,
         family_id fid,
         def * d,
-        std::string & name,
         unsigned case_index,
         sort_ref_vector const & arg_sorts,
         expr_ref_vector const& guards, 
@@ -44,10 +43,10 @@ namespace recfun {
         : m_pred(m),
           m_guards(guards),
           m_rhs(expr_ref(rhs,m)), 
-          m_def(d) {        
-        parameter p(case_index);
-        func_decl_info info(fid, OP_FUN_CASE_PRED, 1, &p);
-        m_pred = m.mk_func_decl(symbol(name.c_str()), arg_sorts.size(), arg_sorts.data(), m.mk_bool_sort(), info);
+          m_def(d) {
+        parameter ps[2] = { parameter(case_index), parameter(d->get_decl()) };
+        func_decl_info info(fid, OP_FUN_CASE_PRED, 2, ps);
+        m_pred = m.mk_func_decl(symbol("case-def"), arg_sorts.size(), arg_sorts.data(), m.mk_bool_sort(), info);
     }
 
     def::def(ast_manager &m, family_id fid, symbol const & s,
@@ -220,11 +219,10 @@ namespace recfun {
     }
 
 
-    void def::add_case(std::string & name, unsigned case_index, expr_ref_vector const& conditions, expr * rhs, bool is_imm) {
-        case_def c(m, m_fid, this, name, case_index, get_domain(), conditions, rhs);
+    void def::add_case(unsigned case_index, expr_ref_vector const& conditions, expr * rhs, bool is_imm) {
+        case_def c(m, m_fid, this, case_index, get_domain(), conditions, rhs);
         c.set_is_immediate(is_imm);
-        TRACEFN("add_case " << name 
-                << "\n" << mk_pp(rhs, m)
+        TRACEFN("add_case " << case_index << " " <<  mk_pp(rhs, m)
                 << "\n:is_imm " << is_imm
                 << "\n:guards " << conditions);
         m_cases.push_back(c);
@@ -261,7 +259,7 @@ namespace recfun {
         // is the function a macro (unconditional body)?
         if (is_macro || n_vars == 0 || !contains_ite(u, rhs)) {
             // constant function or trivial control flow, only one (dummy) case
-            add_case(name, 0, conditions, rhs);
+            add_case(0, conditions, rhs);
             return;
         }
 
@@ -347,7 +345,7 @@ namespace recfun {
                 
                 // yield new case
                 bool is_imm = is_i(case_rhs);
-                add_case(name, case_idx++, conditions, case_rhs, is_imm);
+                add_case(case_idx++, conditions, case_rhs, is_imm);
             }
         }
 
@@ -436,6 +434,12 @@ namespace recfun {
             return *(m_util.get());
         }
 
+        void plugin::get_op_names(svector<builtin_name> & op_names, symbol const & logic) {
+            op_names.push_back(builtin_name("case-def", OP_FUN_CASE_PRED));
+            op_names.push_back(builtin_name("recfun-num-rounds", OP_NUM_ROUNDS));
+        }
+
+
         promise_def plugin::mk_def(symbol const& name, unsigned n, sort *const * params, sort * range, bool is_generated) {
             def* d = u().decl_fun(name, n, params, range, is_generated);
             SASSERT(!m_defs.contains(d->get_decl()));
@@ -498,6 +502,18 @@ namespace recfun {
         func_decl * plugin::mk_func_decl(decl_kind k, unsigned num_parameters, parameter const * parameters, 
                                          unsigned arity, sort * const * domain, sort * range)
         {
+            func_decl_info info(get_family_id(), k, num_parameters, parameters);
+            switch (k) {
+            case OP_FUN_CASE_PRED: 
+                SASSERT(num_parameters == 2);
+                return m().mk_func_decl(symbol("case-def"), arity, domain, m().mk_bool_sort(), info);
+            case OP_NUM_ROUNDS: 
+                SASSERT(num_parameters == 1);
+                SASSERT(arity == 0);
+                return m().mk_const_decl(symbol("recfun-num-rounds"), m().mk_bool_sort(), info);                
+            default:
+                break;
+            }
             UNREACHABLE();
             return nullptr;            
         }
diff --git a/src/ast/recfun_decl_plugin.h b/src/ast/recfun_decl_plugin.h
index bb75a854c..ae9c060e9 100644
--- a/src/ast/recfun_decl_plugin.h
+++ b/src/ast/recfun_decl_plugin.h
@@ -72,7 +72,6 @@ namespace recfun {
         case_def(ast_manager & m,
                  family_id fid,
                  def * d,
-                 std::string & name,
                  unsigned case_index,
                  sort_ref_vector const & arg_sorts,
                  expr_ref_vector const& guards,
@@ -124,7 +123,7 @@ namespace recfun {
         // compute cases for a function, given its RHS (possibly containing `ite`).
         void compute_cases(util& u, replace& subst, is_immediate_pred &, 
                            bool is_macro, unsigned n_vars, var *const * vars, expr* rhs);
-        void add_case(std::string & name, unsigned case_index, expr_ref_vector const& conditions, expr* rhs, bool is_imm = false);
+        void add_case(unsigned case_index, expr_ref_vector const& conditions, expr* rhs, bool is_imm = false);
         bool contains_ite(util& u, expr* e); // expression contains a test over a def?
         bool contains_def(util& u, expr* e); // expression contains a def
     public:
@@ -190,6 +189,8 @@ namespace recfun {
         
             func_decl * mk_func_decl(decl_kind k, unsigned num_parameters, parameter const * parameters, 
                                      unsigned arity, sort * const * domain, sort * range) override;
+
+            void get_op_names(svector<builtin_name> & op_names, symbol const & logic) override;
             
             promise_def mk_def(symbol const& name, unsigned n, sort *const * params, sort * range, bool is_generated = false);
 
diff --git a/src/cmd_context/cmd_context.cpp b/src/cmd_context/cmd_context.cpp
index 2d90b70c3..5602f53a3 100644
--- a/src/cmd_context/cmd_context.cpp
+++ b/src/cmd_context/cmd_context.cpp
@@ -1085,7 +1085,12 @@ func_decl * cmd_context::find_func_decl(symbol const & s, unsigned num_indices,
             throw cmd_exception("invalid function declaration reference, invalid builtin reference ", s);
         return f;
     }
-    throw cmd_exception("invalid function declaration reference, unknown function ", s);
+    if (num_indices > 0 && m_func_decls.find(s, fs)) 
+        f = fs.find(m(), arity, domain, range);
+    if (f) 
+        return f;
+
+    throw cmd_exception("invalid function declaration reference, unknown indexed function ", s);
 }
 
 psort_decl * cmd_context::find_psort_decl(symbol const & s) const {
@@ -1134,12 +1139,10 @@ bool cmd_context::try_mk_builtin_app(symbol const & s, unsigned num_args, expr *
         fid = d2.m_fid;
         k   = d2.m_decl;
     }
-    if (num_indices == 0) {
-        result = m().mk_app(fid, k, 0, nullptr, num_args, args, range);
-    }
-    else {
-        result = m().mk_app(fid, k, num_indices, indices, num_args, args, range);
-    }
+    if (num_indices == 0) 
+        result = m().mk_app(fid, k, 0, nullptr, num_args, args, range);    
+    else 
+        result = m().mk_app(fid, k, num_indices, indices, num_args, args, range);    
     CHECK_SORT(result.get());
     return nullptr != result.get();
 }
diff --git a/src/tactic/bv/bit_blaster_model_converter.cpp b/src/tactic/bv/bit_blaster_model_converter.cpp
index 88ff11683..9a423452f 100644
--- a/src/tactic/bv/bit_blaster_model_converter.cpp
+++ b/src/tactic/bv/bit_blaster_model_converter.cpp
@@ -148,6 +148,7 @@ struct bit_blaster_model_converter : public model_converter {
             for (expr* bit : *to_app(bs)) {
                 func_decl * bit_decl = to_app(bit)->get_decl();
                 expr * bit_val = old_model->get_const_interp(bit_decl);
+                CTRACE("bv", !bit_val, tout << mk_pp(bit, m()) << " " << *old_model << "\n");
                 SASSERT(bit_val);
                 vals.push_back(bit_val);
             }