1 files changed, 6 insertions, 8 deletions
diff --git a/src/theory/strings/strings_rewriter.cpp b/src/theory/strings/strings_rewriter.cpp
index 932b5c8cc..575c33501 100644
--- a/src/theory/strings/strings_rewriter.cpp
+++ b/src/theory/strings/strings_rewriter.cpp
@@ -251,15 +251,13 @@ Node StringsRewriter::rewriteStringLeq(Node n)
   {
     String s = n1[0].getConst<String>();
     String t = n2[0].getConst<String>();
-    // only need to truncate if s is longer
-    if (s.size() > t.size())
+    size_t prefixLen = std::min(s.size(), t.size());
+    s = s.prefix(prefixLen);
+    t = t.prefix(prefixLen);
+    // if the prefixes are not the same, then we can already decide the outcome
+    if (s != t)
     {
-      s = s.prefix(t.size());
-    }
-    // if prefix is not leq, then entire string is not leq
-    if (!s.isLeq(t))
-    {
-      Node ret = nm->mkConst(false);
+      Node ret = nm->mkConst(s.isLeq(t));
       return returnRewrite(n, ret, Rewrite::STR_LEQ_CPREFIX);
     }
   }