From 7ad41fe71b9f7d206ee6d1c642bb7926bffea6c7 Mon Sep 17 00:00:00 2001 From: yoni206 Date: Tue, 28 Jul 2020 10:44:55 -0700 Subject: Supporting seq.nth (#4723) This PR adds support for seq.nth operator by eliminating it during expandDefinitions, based on sub-sequences. Tests that use this operator are also included. --- src/theory/strings/skolem_cache.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'src/theory/strings/skolem_cache.h') diff --git a/src/theory/strings/skolem_cache.h b/src/theory/strings/skolem_cache.h index 302c69e83..755f70833 100644 --- a/src/theory/strings/skolem_cache.h +++ b/src/theory/strings/skolem_cache.h @@ -138,6 +138,11 @@ class SkolemCache // where b is a regular expression, n is the number of occurrences of b // in a, and k(0)=0. SK_OCCUR_LEN, + // For function k: ((Seq U) x Int) -> U + // exists k. + // forall s, n. + // k(s, n) is some undefined value of sort U + SK_NTH, }; /** * Returns a skolem of type string that is cached for (a,b,id) and has -- cgit v1.2.3