	bdd_ptr image = bdd_and_abstract(self->dd, b, ssr, BddEnc_get_state_vars_cube(self->enc));
	bdd_ref(image);
	bdd_ptr supersets_in_reach = BddEnc_next_state_var_to_state_var(self->enc, image);
	bdd_ref(supersets_in_reach);
	bdd_ptr not_super = bdd_not(self->dd, supersets_in_reach);
	bdd_ref(not_super);
	bdd_ptr minimals = bdd_and(self->dd, a, not_super);
	bdd_ref(minimals);
