fix #6637

Z3Prover · Mar 22, 2023 · 2683a2d · 2683a2d
1 parent 53ca65a
commit 2683a2d
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Showing 2 changed files with 4 additions and 3 deletions.
diff --git a/src/math/lp/nla_divisions.cpp b/src/math/lp/nla_divisions.cpp
@@ -58,10 +58,11 @@ namespace nla {
 
         auto monotonicity1 = [&](auto x1, auto& x1val, auto y1, auto& y1val, auto& q1, auto& q1val,
             auto x2, auto& x2val, auto y2, auto& y2val, auto& q2, auto& q2val) {
-                if (y1val >= y2val && y2val > 0 && x1val <= x2val && q1val > q2val) {
-                    new_lemma lemma(c, "y1 >= y2 > 0 & x1 <= x2 => x1/y1 <= x2/y2");
+                if (y1val >= y2val && y2val > 0 && 0 <= x1val && x1val <= x2val && q1val > q2val) {
+                    new_lemma lemma(c, "y1 >= y2 > 0 & 0 <= x1 <= x2 => x1/y1 <= x2/y2");
                     lemma |= ineq(term(y1, rational(-1), y2), llc::LT, 0);
                     lemma |= ineq(y2, llc::LE, 0);
+                    lemma |= ineq(x1, llc::LT, 0);
                     lemma |= ineq(term(x1, rational(-1), x2), llc::GT, 0);
                     lemma |= ineq(term(q1, rational(-1), q2), llc::LE, 0);
                     return true;

diff --git a/src/sat/smt/euf_proof_checker.h b/src/sat/smt/euf_proof_checker.h
@@ -35,7 +35,7 @@ namespace euf {
         virtual bool check(app* jst) = 0;
         virtual expr_ref_vector clause(app* jst) = 0;
         virtual void register_plugins(theory_checker& pc) = 0;
-        virtual bool vc(app* jst, expr_ref_vector const& clause, expr_ref_vector& v) { v.reset(); v.append(this->clause(jst)); return false; }
+        virtual bool vc(app* jst, expr_ref_vector const& clause, expr_ref_vector& v) { v.append(this->clause(jst)); return false; }
     };
 
     class theory_checker {