void subst(contains_app& x, rational const& vl, expr_ref& fml, expr_ref* def) override {
app_ref c(m_bv.mk_numeral(vl, m_bv.get_bv_size(x.x())), m);
m_replace.apply_substitution(x.x(), c, fml);
if (def) {
*def = m_bv.mk_numeral(vl, m_bv.get_bv_size(x.x()));
}
}
bool get_num_branches(contains_app& x, expr* fml, rational& nb) override {
unsigned sz = m_bv.get_bv_size(x.x());
nb = power(rational(2), sz);
return true;
}