diff --git a/src/ast/datatype_decl_plugin.h b/src/ast/datatype_decl_plugin.h
index 3b4c8dd08..840329dda 100644
--- a/src/ast/datatype_decl_plugin.h
+++ b/src/ast/datatype_decl_plugin.h
@@ -16,7 +16,7 @@ Author:
 Revision History:
 
 --*/
-// define DATATYPE_V2
+#define DATATYPE_V2
 #ifdef DATATYPE_V2
 #include "ast/datatype_decl_plugin2.h"
 #else
diff --git a/src/ast/datatype_decl_plugin2.cpp b/src/ast/datatype_decl_plugin2.cpp
index 41ae2e839..fa3c73bca 100644
--- a/src/ast/datatype_decl_plugin2.cpp
+++ b/src/ast/datatype_decl_plugin2.cpp
@@ -236,7 +236,7 @@ namespace datatype {
             return m.mk_func_decl(symbol("update-field"), arity, domain, range, info);
         }
 
-#define VALIDATE_PARAM(_pred_) if (!(_pred_)) m_manager->raise_exception("invalid parameter to datatype function");
+#define VALIDATE_PARAM(_pred_) if (!(_pred_)) m_manager->raise_exception("invalid parameter to datatype function "  #_pred_);
         
         func_decl * decl::plugin::mk_constructor(unsigned num_parameters, parameter const * parameters, 
                                                  unsigned arity, sort * const * domain, sort * range) {
@@ -252,13 +252,26 @@ namespace datatype {
         func_decl * decl::plugin::mk_recognizer(unsigned num_parameters, parameter const * parameters, 
                                                 unsigned arity, sort * const * domain, sort *) {
             ast_manager& m = *m_manager;
-            VALIDATE_PARAM(arity == 1 && num_parameters == 1 && parameters[0].is_ast() && is_func_decl(parameters[0].get_ast()));
+            VALIDATE_PARAM(arity == 1 && num_parameters == 2 && parameters[1].is_symbol() && parameters[0].is_ast() && is_func_decl(parameters[0].get_ast()));
             VALIDATE_PARAM(u().is_datatype(domain[0]));
             // blindly trust that parameter is a constructor
             sort* range = m_manager->mk_bool_sort();
             func_decl* f = to_func_decl(parameters[0].get_ast());
             func_decl_info info(m_family_id, OP_DT_RECOGNISER, num_parameters, parameters);
             info.m_private_parameters = true;
+            return m.mk_func_decl(symbol(parameters[1].get_symbol()), arity, domain, range, info);
+        }
+
+        func_decl * decl::plugin::mk_is(unsigned num_parameters, parameter const * parameters, 
+                                                unsigned arity, sort * const * domain, sort *) {
+            ast_manager& m = *m_manager;
+            VALIDATE_PARAM(arity == 1 && num_parameters == 1 && parameters[0].is_ast() && is_func_decl(parameters[0].get_ast()));
+            VALIDATE_PARAM(u().is_datatype(domain[0]));
+            // blindly trust that parameter is a constructor
+            sort* range = m_manager->mk_bool_sort();
+            func_decl* f = to_func_decl(parameters[0].get_ast());
+            func_decl_info info(m_family_id, OP_DT_IS, num_parameters, parameters);
+            info.m_private_parameters = true;
             return m.mk_func_decl(symbol("is"), arity, domain, range, info);
         }
 
@@ -282,6 +295,8 @@ namespace datatype {
                 return mk_constructor(num_parameters, parameters, arity, domain, range);
             case OP_DT_RECOGNISER:
                 return mk_recognizer(num_parameters, parameters, arity, domain, range);                
+            case OP_DT_IS:
+                return mk_is(num_parameters, parameters, arity, domain, range);                
             case OP_DT_ACCESSOR:
                 return mk_accessor(num_parameters, parameters, arity, domain, range);                
             case OP_DT_UPDATE_FIELD: 
@@ -297,20 +312,6 @@ namespace datatype {
             return alloc(def, m, u(), name, m_class_id, n, params);
         }
 
-#if 0
-        def& plugin::add(symbol const& name, unsigned n, sort * const * params) {
-            ast_manager& m = *m_manager;
-            def* d = 0;
-            if (m_defs.find(name, d)) {
-                TRACE("datatype", tout << "delete previous version for " << name << "\n";);
-                dealloc(d);
-            }
-            d = alloc(def, m, u(), name, m_class_id, n, params);
-            m_defs.insert(name, d);
-            m_def_block.push_back(name);
-            return *d;
-        }
-#endif
 
         void plugin::end_def_block() {
             ast_manager& m = *m_manager;
@@ -407,7 +408,7 @@ namespace datatype {
         }
         
         void plugin::get_op_names(svector<builtin_name> & op_names, symbol const & logic) {
-            op_names.push_back(builtin_name("is", OP_DT_RECOGNISER));
+            op_names.push_back(builtin_name("is", OP_DT_IS));
             if (logic == symbol::null) {
                 op_names.push_back(builtin_name("update-field", OP_DT_UPDATE_FIELD));
             }
@@ -739,18 +740,25 @@ namespace datatype {
         return res;
     }
 
-    func_decl * util::get_constructor_recognizer(func_decl * constructor) {
-        SASSERT(is_constructor(constructor));
+    func_decl * util::get_constructor_recognizer(func_decl * con) {
+        SASSERT(is_constructor(con));
         func_decl * d = 0;
-        if (m_constructor2recognizer.find(constructor, d))
+        if (m_constructor2recognizer.find(con, d))
             return d;
-        sort * datatype = constructor->get_range();
-        parameter ps[1] = { parameter(constructor) };
-        d  = m.mk_func_decl(m_family_id, OP_DT_RECOGNISER, 1, ps, 1, &datatype);
+        sort * datatype = con->get_range();
+        def const& dd = get_def(datatype);
+        symbol r;
+        for (constructor const* c : dd) {
+            if (c->name() == con->get_name()) {
+                r = c->recognizer();
+            }
+        }
+        parameter ps[2] = { parameter(con), parameter(r) };
+        d  = m.mk_func_decl(m_family_id, OP_DT_RECOGNISER, 2, ps, 1, &datatype);
         SASSERT(d);
-        m_asts.push_back(constructor);
+        m_asts.push_back(con);
         m_asts.push_back(d);
-        m_constructor2recognizer.insert(constructor, d);
+        m_constructor2recognizer.insert(con, d);
         return d;
     }
 
@@ -917,11 +925,11 @@ namespace datatype {
         UNREACHABLE();
         return 0;
     }
+
     unsigned util::get_recognizer_constructor_idx(func_decl * f) const {
         return get_constructor_idx(get_recognizer_constructor(f));
     }
 
-
     /**
        \brief Two datatype sorts s1 and s2 are siblings if they were
        defined together in the same mutually recursive definition.
diff --git a/src/ast/datatype_decl_plugin2.h b/src/ast/datatype_decl_plugin2.h
index d7173b24a..f076bb43f 100644
--- a/src/ast/datatype_decl_plugin2.h
+++ b/src/ast/datatype_decl_plugin2.h
@@ -36,7 +36,8 @@ Revision History:
     enum op_kind {
         OP_DT_CONSTRUCTOR,
         OP_DT_RECOGNISER,
-        OP_DT_ACCESSOR,
+        OP_DT_IS,
+        OP_DT_ACCESSOR,        
         OP_DT_UPDATE_FIELD,
         LAST_DT_OP
     };
@@ -78,13 +79,15 @@ namespace datatype {
 
     class constructor {
         symbol           m_name;
+        symbol           m_recognizer;
         ptr_vector<accessor> m_accessors;
         def*             m_def;
     public:
-        constructor(symbol n): m_name(n) {}
+        constructor(symbol n, symbol const& r): m_name(n), m_recognizer(r) {}
         ~constructor();
         void add(accessor* a) { m_accessors.push_back(a); a->attach(this); }
         symbol const& name() const { return m_name; }
+        symbol const& recognizer() const { return m_recognizer; }
         ptr_vector<accessor> const& accessors() const { return m_accessors; }
         ptr_vector<accessor>::const_iterator begin() const { return m_accessors.begin(); }
         ptr_vector<accessor>::const_iterator end() const { return m_accessors.end(); }
@@ -290,6 +293,10 @@ namespace datatype {
                 unsigned num_parameters, parameter const * parameters, 
                 unsigned arity, sort * const * domain, sort * range);
 
+            func_decl * mk_is(
+                unsigned num_parameters, parameter const * parameters, 
+                unsigned arity, sort * const * domain, sort * range);
+
             symbol datatype_name(sort * s) const {
                 //SASSERT(u().is_datatype(s));
                 return s->get_parameter(0).get_symbol();
@@ -340,11 +347,15 @@ namespace datatype {
         bool is_enum_sort(sort* s);
         bool is_recursive(sort * ty);
         bool is_constructor(func_decl * f) const { return is_decl_of(f, m_family_id, OP_DT_CONSTRUCTOR); }
-        bool is_recognizer(func_decl * f) const { return is_decl_of(f, m_family_id, OP_DT_RECOGNISER); }
+        bool is_recognizer(func_decl * f) const { return is_recognizer0(f) || is_is(f); }
+        bool is_recognizer0(func_decl * f) const { return is_decl_of(f, m_family_id, OP_DT_RECOGNISER); }
+        bool is_is(func_decl * f) const { return is_decl_of(f, m_family_id, OP_DT_IS); }
         bool is_accessor(func_decl * f) const { return is_decl_of(f, m_family_id, OP_DT_ACCESSOR); }
         bool is_update_field(func_decl * f) const { return is_decl_of(f, m_family_id, OP_DT_UPDATE_FIELD); }
         bool is_constructor(app * f) const { return is_app_of(f, m_family_id, OP_DT_CONSTRUCTOR); }
-        bool is_recognizer(app * f) const { return is_app_of(f, m_family_id, OP_DT_RECOGNISER); }
+        bool is_recognizer0(app * f) const { return is_app_of(f, m_family_id, OP_DT_RECOGNISER);} 
+        bool is_is(app * f) const { return is_app_of(f, m_family_id, OP_DT_IS);} 
+        bool is_recognizer(app * f) const { return is_recognizer0(f) || is_is(f); }
         bool is_accessor(app * f) const { return is_app_of(f, m_family_id, OP_DT_ACCESSOR); }
         bool is_update_field(app * f) const { return is_app_of(f, m_family_id, OP_DT_UPDATE_FIELD); }
         ptr_vector<func_decl> const * get_datatype_constructors(sort * ty);
@@ -401,7 +412,7 @@ inline accessor_decl * mk_accessor_decl(ast_manager& m, symbol const & n, type_r
 }
 
 inline constructor_decl * mk_constructor_decl(symbol const & n, symbol const & r, unsigned num_accessors, accessor_decl * * acs) {
-    constructor_decl* c = alloc(constructor_decl, n);
+    constructor_decl* c = alloc(constructor_decl, n, r);
     for (unsigned i = 0; i < num_accessors; ++i) {
         c->add(acs[i]);
     }
diff --git a/src/ast/rewriter/datatype_rewriter.cpp b/src/ast/rewriter/datatype_rewriter.cpp
index 9efa61f70..f0a95929b 100644
--- a/src/ast/rewriter/datatype_rewriter.cpp
+++ b/src/ast/rewriter/datatype_rewriter.cpp
@@ -23,6 +23,7 @@ br_status datatype_rewriter::mk_app_core(func_decl * f, unsigned num_args, expr
     switch(f->get_decl_kind()) {
     case OP_DT_CONSTRUCTOR: return BR_FAILED;
     case OP_DT_RECOGNISER:
+    case OP_DT_IS:
         //
         // simplify is_cons(cons(x,y)) -> true
         // simplify is_cons(nil) -> false
diff --git a/src/ast/rewriter/poly_rewriter_def.h b/src/ast/rewriter/poly_rewriter_def.h
index b52440393..39c4a1078 100644
--- a/src/ast/rewriter/poly_rewriter_def.h
+++ b/src/ast/rewriter/poly_rewriter_def.h
@@ -753,18 +753,14 @@ br_status poly_rewriter<Config>::cancel_monomials(expr * lhs, expr * rhs, bool m
 
     normalize(c);
 
-    TRACE("mk_le_bug", tout << c << "\n";);
-
     if (!has_multiple && num_coeffs <= 1) {
         if (move) {
             if (is_numeral(rhs)) {
-                TRACE("mk_le_bug", tout << "rhs is numeral\n";);
                 return BR_FAILED;
             }
         }
         else {
             if (num_coeffs == 0 || is_numeral(rhs)) {
-                TRACE("mk_le_bug", tout << "rhs is numeral or no coeffs\n";);
                 return BR_FAILED;
             }
         }
diff --git a/src/ast/static_features.cpp b/src/ast/static_features.cpp
index 3c8333d02..3db4d02a2 100644
--- a/src/ast/static_features.cpp
+++ b/src/ast/static_features.cpp
@@ -145,18 +145,19 @@ bool static_features::is_diff_atom(expr const * e) const {
         return true;    
     if (!is_numeral(rhs)) 
         return false;    
-    // lhs can be 'x' or '(+ x (* -1 y))'
+    // lhs can be 'x' or '(+ x (* -1 y))' or '(+ (* -1 x) y)'
     if (!is_arith_expr(lhs))
         return true;
     expr* arg1, *arg2;
     if (!m_autil.is_add(lhs, arg1, arg2)) 
         return false;    
-    // x
-    if (is_arith_expr(arg1))
-        return false;
-    // arg2: (* -1 y)
     expr* m1, *m2;
-    return m_autil.is_mul(arg2, m1, m2) &&  is_minus_one(m1) && !is_arith_expr(m2);
+    if (!is_arith_expr(arg1) && m_autil.is_mul(arg2, m1, m2) &&  is_minus_one(m1) && !is_arith_expr(m2))
+        return true;
+    if (!is_arith_expr(arg2) && m_autil.is_mul(arg1, m1, m2) &&  is_minus_one(m1) && !is_arith_expr(m2))
+        return true;
+    return false;
+    
 }
 
 bool static_features::is_gate(expr const * e) const {
diff --git a/src/cmd_context/basic_cmds.cpp b/src/cmd_context/basic_cmds.cpp
index c81170ba4..21b66febd 100644
--- a/src/cmd_context/basic_cmds.cpp
+++ b/src/cmd_context/basic_cmds.cpp
@@ -15,21 +15,21 @@ Author:
 Notes:
 
 --*/
-#include "cmd_context/cmd_context.h"
+#include "util/gparams.h"
+#include "util/env_params.h"
 #include "util/version.h"
 #include "ast/ast_smt_pp.h"
 #include "ast/ast_smt2_pp.h"
 #include "ast/ast_pp.h"
-#include "model/model_smt2_pp.h"
 #include "ast/array_decl_plugin.h"
 #include "ast/pp.h"
+#include "ast/well_sorted.h"
+#include "ast/pp_params.hpp"
+#include "model/model_smt2_pp.h"
+#include "cmd_context/cmd_context.h"
 #include "cmd_context/cmd_util.h"
 #include "cmd_context/simplify_cmd.h"
 #include "cmd_context/eval_cmd.h"
-#include "util/gparams.h"
-#include "util/env_params.h"
-#include "ast/well_sorted.h"
-#include "ast/pp_params.hpp"
 
 class help_cmd : public cmd {
     svector<symbol> m_cmds;
@@ -79,19 +79,15 @@ public:
             }
             // named_cmd_lt is not a total order for commands, but this is irrelevant for Linux x Windows behavior
             std::sort(cmds.begin(), cmds.end(), named_cmd_lt());
-            vector<named_cmd>::const_iterator it2  = cmds.begin();
-            vector<named_cmd>::const_iterator end2 = cmds.end();
-            for (; it2 != end2; ++it2) {
-                display_cmd(ctx, it2->first, it2->second);
+            for (named_cmd const& nc : cmds) {
+                display_cmd(ctx, nc.first, nc.second);
             }
         }
         else {
-            svector<symbol>::const_iterator it  = m_cmds.begin();
-            svector<symbol>::const_iterator end = m_cmds.end();
-            for (; it != end; ++it) {
-                cmd * c = ctx.find_cmd(*it);
+            for (symbol const& s : m_cmds) {
+                cmd * c = ctx.find_cmd(s);
                 SASSERT(c);
-                display_cmd(ctx, *it, c);
+                display_cmd(ctx, s, c);
             }
         }
         ctx.regular_stream() << "\"\n";
@@ -136,11 +132,10 @@ ATOMIC_CMD(get_assignment_cmd, "get-assignment", "retrieve assignment", {
     ctx.get_check_sat_result()->get_model(m);
     ctx.regular_stream() << "(";
     dictionary<macro_decls> const & macros = ctx.get_macros();
-    dictionary<macro_decls>::iterator it  = macros.begin();
-    dictionary<macro_decls>::iterator end = macros.end();
-    for (bool first = true; it != end; ++it) {
-        symbol const & name = (*it).m_key;
-        macro_decls const & _m    = (*it).m_value;
+    bool first = true;
+    for (auto const& kv : macros) {
+        symbol const & name = kv.m_key;
+        macro_decls const & _m    = kv.m_value;
         for (auto md : _m) {
             if (md.m_domain.size() == 0 && ctx.m().is_bool(md.m_body)) {
                 expr_ref val(ctx.m());
@@ -211,14 +206,13 @@ static void print_core(cmd_context& ctx) {
     ptr_vector<expr> core;
     ctx.get_check_sat_result()->get_unsat_core(core);
     ctx.regular_stream() << "(";
-    ptr_vector<expr>::const_iterator it  = core.begin();
-    ptr_vector<expr>::const_iterator end = core.end();
-    for (bool first = true; it != end; ++it) {
+    bool first = true;
+    for (expr* e : core) {
     if (first)
         first = false;
     else
         ctx.regular_stream() << " ";
-    ctx.regular_stream() << mk_ismt2_pp(*it, ctx.m());
+    ctx.regular_stream() << mk_ismt2_pp(e, ctx.m());
     }
     ctx.regular_stream() << ")" << std::endl;
 }
diff --git a/src/cmd_context/cmd_context.cpp b/src/cmd_context/cmd_context.cpp
index e93e51186..c0e1c9f9c 100644
--- a/src/cmd_context/cmd_context.cpp
+++ b/src/cmd_context/cmd_context.cpp
@@ -18,7 +18,10 @@ Notes:
 
 #include<signal.h>
 #include "util/tptr.h"
-#include "cmd_context/cmd_context.h"
+#include "util/cancel_eh.h"
+#include "util/scoped_ctrl_c.h"
+#include "util/dec_ref_util.h"
+#include "util/scoped_timer.h"
 #include "ast/func_decl_dependencies.h"
 #include "ast/arith_decl_plugin.h"
 #include "ast/bv_decl_plugin.h"
@@ -31,22 +34,19 @@ Notes:
 #include "ast/rewriter/var_subst.h"
 #include "ast/pp.h"
 #include "ast/ast_smt2_pp.h"
-#include "cmd_context/basic_cmds.h"
-#include "util/cancel_eh.h"
-#include "util/scoped_ctrl_c.h"
-#include "util/dec_ref_util.h"
 #include "ast/decl_collector.h"
 #include "ast/well_sorted.h"
-#include "model/model_evaluator.h"
 #include "ast/for_each_expr.h"
-#include "util/scoped_timer.h"
-#include "cmd_context/interpolant_cmds.h"
+#include "ast/rewriter/th_rewriter.h"
+#include "model/model_evaluator.h"
 #include "model/model_smt2_pp.h"
 #include "model/model_v2_pp.h"
 #include "model/model_params.hpp"
-#include "ast/rewriter/th_rewriter.h"
 #include "tactic/tactic_exception.h"
 #include "solver/smt_logics.h"
+#include "cmd_context/basic_cmds.h"
+#include "cmd_context/interpolant_cmds.h"
+#include "cmd_context/cmd_context.h"
 
 func_decls::func_decls(ast_manager & m, func_decl * f):
     m_decls(TAG(func_decl*, f, 0)) {
@@ -61,11 +61,9 @@ void func_decls::finalize(ast_manager & m) {
     else {
         TRACE("func_decls", tout << "finalize...\n";);
         func_decl_set * fs = UNTAG(func_decl_set *, m_decls);
-        func_decl_set::iterator it  = fs->begin();
-        func_decl_set::iterator end = fs->end();
-        for (; it != end; ++it) {
-            TRACE("func_decls", tout << "dec_ref of " << (*it)->get_name() << " ref_count: " << (*it)->get_ref_count() << "\n";);
-            m.dec_ref(*it);
+        for (func_decl * f : *fs) {
+            TRACE("func_decls", tout << "dec_ref of " << f->get_name() << " ref_count: " << f->get_ref_count() << "\n";);
+            m.dec_ref(f);
         }
         dealloc(fs);
     }
@@ -161,10 +159,7 @@ bool func_decls::clash(func_decl * f) const {
     if (GET_TAG(m_decls) == 0)
         return false;
     func_decl_set * fs = UNTAG(func_decl_set *, m_decls);
-    func_decl_set::iterator it  = fs->begin();
-    func_decl_set::iterator end = fs->end();
-    for (; it != end; ++it) {
-        func_decl * g = *it;
+    for (func_decl * g : *fs) {
         if (g == f)
             continue;
         if (g->get_arity() != f->get_arity())
@@ -201,10 +196,7 @@ func_decl * func_decls::find(unsigned arity, sort * const * domain, sort * range
     if (!more_than_one())
         return first();
     func_decl_set * fs = UNTAG(func_decl_set *, m_decls);
-    func_decl_set::iterator it  = fs->begin();
-    func_decl_set::iterator end = fs->end();
-    for (; it != end; it++) {
-        func_decl * f = *it;
+    for (func_decl * f : *fs) {
         if (range != 0 && f->get_range() != range)
             continue;
         if (f->get_arity() != arity)
@@ -1957,11 +1949,9 @@ void cmd_context::dt_eh::operator()(sort * dt, pdecl* pd) {
     for (func_decl * c : *m_dt_util.get_datatype_constructors(dt)) {
         TRACE("new_dt_eh", tout << "new constructor: " << c->get_name() << "\n";);
         m_owner.insert(c);        
-#ifndef DATATYPE_V2
         func_decl * r = m_dt_util.get_constructor_recognizer(c);
         m_owner.insert(r);
         TRACE("new_dt_eh", tout << "new recognizer: " << r->get_name() << "\n";);
-#endif
         for (func_decl * a : *m_dt_util.get_constructor_accessors(c)) {
             TRACE("new_dt_eh", tout << "new accessor: " << a->get_name() << "\n";);
             m_owner.insert(a);            
diff --git a/src/cmd_context/pdecl.cpp b/src/cmd_context/pdecl.cpp
index 4417061ec..9d6c5065e 100644
--- a/src/cmd_context/pdecl.cpp
+++ b/src/cmd_context/pdecl.cpp
@@ -267,8 +267,8 @@ public:
 
 psort_decl::psort_decl(unsigned id, unsigned num_params, pdecl_manager & m, symbol const & n):
     pdecl(id, num_params),
-    m_psort_kind(PSORT_BASE),
     m_name(n),
+    m_psort_kind(PSORT_BASE),
     m_inst_cache(0) {
 }
 
diff --git a/src/cmd_context/tactic_cmds.cpp b/src/cmd_context/tactic_cmds.cpp
index b5ad0707d..3eafc6bbd 100644
--- a/src/cmd_context/tactic_cmds.cpp
+++ b/src/cmd_context/tactic_cmds.cpp
@@ -255,11 +255,9 @@ public:
             result->m_core.append(core_elems.size(), core_elems.c_ptr());
             if (p.get_bool("print_unsat_core", false)) {
                 ctx.regular_stream() << "(unsat-core";
-                ptr_vector<expr>::const_iterator it  = core_elems.begin();
-                ptr_vector<expr>::const_iterator end = core_elems.end();
-                for (; it != end; ++it) {
+                for (expr * e : core_elems) {
                     ctx.regular_stream() << " ";
-                    ctx.display(ctx.regular_stream(), *it);
+                    ctx.display(ctx.regular_stream(), e);
                 }
                 ctx.regular_stream() << ")" << std::endl;
             }
diff --git a/src/smt/theory_dense_diff_logic_def.h b/src/smt/theory_dense_diff_logic_def.h
index 342766c04..ad7727a89 100644
--- a/src/smt/theory_dense_diff_logic_def.h
+++ b/src/smt/theory_dense_diff_logic_def.h
@@ -127,7 +127,7 @@ namespace smt {
         if (!m_non_diff_logic_exprs) {
             TRACE("non_diff_logic", tout << "found non diff logic expression:\n" << mk_pp(n, get_manager()) << "\n";);
             get_context().push_trail(value_trail<context, bool>(m_non_diff_logic_exprs));
-        IF_VERBOSE(0, verbose_stream() << "(smt.diff_logic: non-diff logic expression " << mk_pp(n, get_manager()) << ")\n";); 
+            IF_VERBOSE(0, verbose_stream() << "(smt.diff_logic: non-diff logic expression " << mk_pp(n, get_manager()) << ")\n";); 
             m_non_diff_logic_exprs = true;
         }
     }
@@ -154,6 +154,9 @@ namespace smt {
         if (m_autil.is_add(lhs) && to_app(lhs)->get_num_args() == 2 && is_times_minus_one(to_app(lhs)->get_arg(1), s)) {
             t = to_app(to_app(lhs)->get_arg(0));
         }
+        else if (m_autil.is_add(lhs) && to_app(lhs)->get_num_args() == 2 && is_times_minus_one(to_app(lhs)->get_arg(0), s)) {
+            t = to_app(to_app(lhs)->get_arg(1));
+        }
         else if (m_autil.is_mul(lhs) && to_app(lhs)->get_num_args() == 2 && m_autil.is_minus_one(to_app(lhs)->get_arg(0))) {
             s = to_app(to_app(lhs)->get_arg(1));
             t = mk_zero_for(s);
diff --git a/src/test/get_consequences.cpp b/src/test/get_consequences.cpp
index 229cbe834..b9a54245e 100644
--- a/src/test/get_consequences.cpp
+++ b/src/test/get_consequences.cpp
@@ -65,12 +65,12 @@ void test2() {
     constructor_decl* G = mk_constructor_decl(symbol("G"), symbol("is-G"), 0, 0);
     constructor_decl* B = mk_constructor_decl(symbol("B"), symbol("is-B"), 0, 0);
     constructor_decl* constrs[3] = { R, G, B };
-    datatype_decl * enum_sort = mk_datatype_decl(dtutil, symbol("RGB"), 3, constrs);
+    datatype_decl * enum_sort = mk_datatype_decl(dtutil, symbol("RGB"), 0, nullptr, 3, constrs);
     VERIFY(dt.mk_datatypes(1, &enum_sort, 0, 0, new_sorts));    
     sort* rgb = new_sorts[0].get();
 
     expr_ref x = mk_const(m, "x", rgb), y = mk_const(m, "y", rgb), z = mk_const(m, "z", rgb);
-    ptr_vector<func_decl> const& enums = dtutil.get_datatype_constructors(rgb);
+    ptr_vector<func_decl> const& enums = *dtutil.get_datatype_constructors(rgb);
     expr_ref r = expr_ref(m.mk_const(enums[0]), m);
     expr_ref g = expr_ref(m.mk_const(enums[1]), m);
     expr_ref b = expr_ref(m.mk_const(enums[2]), m);