From 3dc56426a37bf85f82ed6dc8cf15e4eb81498110 Mon Sep 17 00:00:00 2001
From: Andrew Reynolds <andrew.j.reynolds@gmail.com>
Date: Wed, 20 May 2020 22:27:04 -0500
Subject: [PATCH] Throw logic exception for equality between regular
 expressions (#4505)

Fixes #4503.
---
 src/theory/strings/term_registry.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/theory/strings/term_registry.cpp b/src/theory/strings/term_registry.cpp
index 3d898b40b..ec034b0c9 100644
--- a/src/theory/strings/term_registry.cpp
+++ b/src/theory/strings/term_registry.cpp
@@ -88,6 +88,12 @@ void TermRegistry::preRegisterTerm(TNode n)
   }
   if (k == EQUAL)
   {
+    if (n[0].getType().isRegExp())
+    {
+      std::stringstream ss;
+      ss << "Equality between regular expressions is not supported";
+      throw LogicException(ss.str());
+    }
     d_ee.addTriggerEquality(n);
     return;
   }
-- 
2.30.2