fixes to bv/dual-solver,

src/ast/arith_decl_plugin.h

@@ -245,7 +245,7 @@ public:
     bool is_unsigned(expr const * n, unsigned& u) const { 
         rational val;
         bool is_int = true;
-        return is_numeral(n, val, is_int) && is_int && val.is_unsigned(), u = val.get_unsigned(), true; 
+        return is_numeral(n, val, is_int) && is_int && val.is_unsigned() && (u = val.get_unsigned(), true); 
     }
     bool is_numeral(expr const * n, rational & val, bool & is_int) const;
     bool is_numeral(expr const * n, rational & val) const { bool is_int; return is_numeral(n, val, is_int); }

src/ast/euf/euf_egraph.cpp

@@ -95,7 +95,7 @@ unmerge(a,a')
 - n1 is reinserted. It used to be a root.
 
 
---*/
+*/
 
 #include "ast/euf/euf_egraph.h"
 #include "ast/ast_pp.h"
@@ -317,11 +317,22 @@ namespace euf {
 
     void egraph::set_merge_enabled(enode* n, bool enable_merge) {
         if (enable_merge != n->merge_enabled()) {
+            toggle_merge_enabled(n);
             m_updates.push_back(update_record(n, update_record::toggle_merge()));
-            n->set_merge_enabled(enable_merge);
         }
     }
 
+    void egraph::toggle_merge_enabled(enode* n) {
+       bool enable_merge = !n->merge_enabled();
+       n->set_merge_enabled(enable_merge);         
+       if (n->num_args() > 0) {
+           if (enable_merge)
+               insert_table(n);
+           else
+               m_table.erase(n);
+       }
+    }
+
     void egraph::set_value(enode* n, lbool value) {        
         force_push();
         TRACE("euf", tout << bpp(n) << "\n";);
@@ -362,7 +373,7 @@ namespace euf {
                 undo_node();
                 break;
             case update_record::tag_t::is_toggle_merge:
-                p.r1->set_merge_enabled(!p.r1->merge_enabled());
+                toggle_merge_enabled(p.r1);
                 break;
             case update_record::tag_t::is_set_parent:
                 undo_eq(p.r1, p.n1, p.r2_num_parents);
@@ -520,6 +531,12 @@ namespace euf {
         for (enode* c : enode_class(r1))
             c->m_root = r1;
 
+        for (enode* p : enode_parents(r1)) 
+            if (p->merge_enabled() && !p->is_cgr() && !p->m_cg) {
+               std::cout << bpp(p) << "\n";
+SASSERT(false);
+        }
+
         for (enode* p : enode_parents(r1)) 
             if (p->merge_enabled() && (p->is_cgr() || !p->congruent(p->m_cg))) 
                 insert_table(p);                    

src/ast/euf/euf_egraph.h

@@ -196,6 +196,7 @@ namespace euf {
         void push_to_lca(enode* a, enode* lca);
         void push_congruence(enode* n1, enode* n2, bool commutative);
         void push_todo(enode* n);
+        void toggle_merge_enabled(enode* n);
 
         enode_bool_pair insert_table(enode* p);
 

src/ast/euf/euf_enode.h

@@ -138,7 +138,7 @@ namespace euf {
         bool is_cgr() const { return this == m_cg; }
         bool commutative() const { return m_commutative; }
         void mark_interpreted() { SASSERT(num_args() == 0); m_interpreted = true; }
-        bool merge_enabled() { return m_merge_enabled; }
+        bool merge_enabled() const { return m_merge_enabled; }
 
         enode* get_arg(unsigned i) const { SASSERT(i < num_args()); return m_args[i]; }        
         unsigned hash() const { return m_expr->hash(); }