Lev's fixes

Signed-off-by: Nikolaj Bjorner <[email protected]>

Author: NikolajBjorner

src/smt/theory_seq.cpp

@@ -4996,6 +4996,7 @@ void theory_seq::add_extract_axiom(expr* e) {
     TRACE("seq", tout << mk_pp(e, m) << "\n";);
     expr* s = nullptr, *i = nullptr, *l = nullptr;
     VERIFY(m_util.str.is_extract(e, s, i, l));
+#if 0
     if (is_tail(s, i, l)) {
         add_tail_axiom(e, s);
         return;
@@ -5012,6 +5013,7 @@ void theory_seq::add_extract_axiom(expr* e) {
         add_extract_suffix_axiom(e, s, i);
         return;
     }
+#endif
     expr_ref x(mk_skolem(m_pre, s, i), m);
     expr_ref ls = mk_len(s);
     expr_ref lx = mk_len(x);