Probably quite instable, but included the splitting into the legacy solver

src/ast/rewriter/seq_rewriter.h

@@ -408,6 +408,11 @@ public:
 
     void simplify_split(split_set& s) { m_split.simplify(s); }
 
+    // decompose a membership constraint into a set of pairs of regex splits
+    std::pair<expr*, expr*> split_membership(expr* str, expr* regex, unsigned threshold, split_set& result) const {
+        return m_split.split_membership(str, regex, threshold, result);
+    }
+
     /**
      * check if regular expression is of the form all ++ s ++ all ++ t + u ++ all, where, s, t, u are sequences
      */