From 3d874313d3297215979b002ea75863d12cc1f4de Mon Sep 17 00:00:00 2001
From: Nikolaj Bjorner <nbjorner@microsoft.com>
Date: Wed, 4 Dec 2019 10:31:02 +0300
Subject: [PATCH] fix #2782

---
 src/smt/diff_logic.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/smt/diff_logic.h b/src/smt/diff_logic.h
index 3e34dc6ca..4958a14de 100644
--- a/src/smt/diff_logic.h
+++ b/src/smt/diff_logic.h
@@ -511,6 +511,9 @@ public:
     bool enable_edge(edge_id id) {
         edge& e = m_edges[id];
         bool r = true;
+        if (!is_feasible()) {
+            return false;
+        }
         if (!e.is_enabled()) {
             e.enable(m_timestamp);
             m_last_enabled_edge = id;