#6319

ensure unknown when a lambda is not in beta redex

src/sat/smt/array_axioms.cpp

@@ -700,6 +700,18 @@ namespace array {
             n->unmark1();
     }
 
+    bool solver::check_lambdas() {
+        unsigned num_vars = get_num_vars();
+        for (unsigned i = 0; i < num_vars; i++) {
+            auto* n = var2enode(i);
+            if (a.is_as_array(n->get_expr()) || is_lambda(n->get_expr()))
+                for (euf::enode* p : euf::enode_parents(n))
+                    if (!ctx.is_beta_redex(p, n))
+                        return false;
+        }
+        return true;
+    }
+
     bool solver::is_shared_arg(euf::enode* r) {
         SASSERT(r->is_root());
         for (euf::enode* n : euf::enode_parents(r)) {

src/sat/smt/array_internalize.cpp

@@ -252,6 +252,8 @@ namespace array {
             return p->get_arg(0)->get_root() == n->get_root();
         if (a.is_map(p->get_expr()))
             return true;
+        if (a.is_store(p->get_expr()))
+            return true;
         return false;
     }
 

src/sat/smt/array_solver.cpp

@@ -108,7 +108,9 @@ namespace array {
         if (m_delay_qhead < m_axiom_trail.size()) 
             return sat::check_result::CR_CONTINUE;
 
-        
+        if (!check_lambdas())
+            return sat::check_result::CR_GIVEUP;
+
         // validate_check();
         return sat::check_result::CR_DONE;
     }

src/sat/smt/array_solver.h

@@ -218,6 +218,7 @@ namespace array {
         bool should_prop_upward(var_data const& d) const;
         bool can_beta_reduce(euf::enode* n) const { return can_beta_reduce(n->get_expr()); }
         bool can_beta_reduce(expr* e) const;
+        bool check_lambdas();
 
         var_data& get_var_data(euf::enode* n) { return get_var_data(n->get_th_var(get_id())); }
         var_data& get_var_data(theory_var v) { return *m_var_data[v]; }