fix #2604

Signed-off-by: Nikolaj Bjorner <nbjorner@microsoft.com>

src/ast/rewriter/arith_rewriter.cpp

@@ -87,8 +87,10 @@ br_status arith_rewriter::mk_app_core(func_decl * f, unsigned num_args, expr * c
     default: st = BR_FAILED; break;
     }
     CTRACE("arith_rewriter", st != BR_FAILED, tout << st << ": " << mk_pp(f, m());
-            for (unsigned i = 0; i < num_args; ++i) tout << mk_pp(args[i], m()) << " ";
+           for (unsigned i = 0; i < num_args; ++i) tout << mk_pp(args[i], m()) << " ";
-            tout << "\n==>\n" << mk_pp(result.get(), m()) << "\n";);
+           tout << "\n==>\n" << mk_pp(result.get(), m()) << "\n";
+           tout << "args: " << to_app(result)->get_num_args() << "\n";
+           );
     return st;
 }
 
@@ -527,14 +529,15 @@ bool arith_rewriter::is_arith_term(expr * n) const {
 }
 
 br_status arith_rewriter::mk_eq_core(expr * arg1, expr * arg2, expr_ref & result) {
+    br_status st = BR_FAILED;
     if (m_eq2ineq) {
         result = m().mk_and(m_util.mk_le(arg1, arg2), m_util.mk_ge(arg1, arg2));
-        return BR_REWRITE2;
+        st = BR_REWRITE2;
     }
-    if (m_arith_lhs || is_arith_term(arg1) || is_arith_term(arg2)) {
+    else if (m_arith_lhs || is_arith_term(arg1) || is_arith_term(arg2)) {
-        return mk_le_ge_eq_core(arg1, arg2, EQ, result);
+        st = mk_le_ge_eq_core(arg1, arg2, EQ, result);
     }
-    return BR_FAILED;
+    return st;
 }
 
 expr_ref arith_rewriter::neg_monomial(expr* e) const {

src/ast/rewriter/poly_rewriter_def.h

@@ -117,10 +117,18 @@ expr * poly_rewriter<Config>::mk_mul_app(unsigned num_args, expr * const * args)
                 return new_args[0];
             }
             else {
+                numeral a;
+                if (new_args.size() > 2 && is_numeral(new_args.get(0), a)) {
+                    return mk_mul_app(a, mk_mul_app(new_args.size() - 1, new_args.c_ptr() + 1));
+                }
                 return m().mk_app(get_fid(), mul_decl_kind(), new_args.size(), new_args.c_ptr());
             }
         }
         else {
+            numeral a;
+            if (num_args > 2 && is_numeral(args[0], a)) {
+                return mk_mul_app(a, mk_mul_app(num_args - 1, args + 1));
+            }
             return m().mk_app(get_fid(), mul_decl_kind(), num_args, args);
         }
     }
@@ -180,12 +188,14 @@ br_status poly_rewriter<Config>::mk_flat_mul_core(unsigned num_args, expr * cons
                     flat_args.push_back(args[j]);
                 }
             }
+            br_status st = mk_nflat_mul_core(flat_args.size(), flat_args.c_ptr(), result);
             TRACE("poly_rewriter",
                   tout << "flat mul:\n";
                   for (unsigned i = 0; i < num_args; i++) tout << mk_bounded_pp(args[i], m()) << "\n";
                   tout << "---->\n";
-                  for (unsigned i = 0; i < flat_args.size(); i++) tout << mk_bounded_pp(flat_args[i], m()) << "\n";);
+                  for (unsigned i = 0; i < flat_args.size(); i++) tout << mk_bounded_pp(flat_args[i], m()) << "\n";
-            br_status st = mk_nflat_mul_core(flat_args.size(), flat_args.c_ptr(), result);
+                  tout << st << "\n";
+                  );
             if (st == BR_FAILED) {
                 result = mk_mul_app(flat_args.size(), flat_args.c_ptr());
                 return BR_DONE;

src/smt/theory_arith_core.h

@@ -336,7 +336,7 @@ namespace smt {
     template<typename Ext>
     theory_var theory_arith<Ext>::internalize_mul(app * m) {
         rational _val;
-        TRACE("arith", tout << mk_pp(m, get_manager()) << "\n";);
+        TRACE("arith", tout << m->get_num_args() << " " << mk_pp(m, get_manager()) << "\n";);
         SASSERT(m_util.is_mul(m));
         expr* arg0 = m->get_arg(0);
         expr* arg1 = m->get_arg(1);
@@ -366,7 +366,7 @@ namespace smt {
             add_row_entry<false>(r_id, numeral::one(), s);
             init_row(r_id);
             return s;
-        }
+        }        
         else {
             return internalize_mul_core(m);
         }

src/util/symbol_table.h

@@ -143,7 +143,6 @@ public:
             if (e != nullptr) {
                 m_trail_stack.push_back(e->m_data);
                 e->m_data.m_data = data;
-                return;
             }
             else {
                 m_trail_stack.push_back(dummy);