Description: Version of bj-ceqsalt with a disjoint variable condition on x , V , removing dependency on df-sb and df-clab . Prefer its use over bj-ceqsalt when sufficient (in particular when V is substituted for _V ). (Contributed by BJ, 16-Jun-2019) (Proof modification is discouraged.)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-ceqsaltv | |- ( ( F/ x ps /\ A. x ( x = A -> ( ph <-> ps ) ) /\ A e. V ) -> ( A. x ( x = A -> ph ) <-> ps ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elissetv | |- ( A e. V -> E. x x = A ) |
|
2 | 1 | 3anim3i | |- ( ( F/ x ps /\ A. x ( x = A -> ( ph <-> ps ) ) /\ A e. V ) -> ( F/ x ps /\ A. x ( x = A -> ( ph <-> ps ) ) /\ E. x x = A ) ) |
3 | bj-ceqsalt0 | |- ( ( F/ x ps /\ A. x ( x = A -> ( ph <-> ps ) ) /\ E. x x = A ) -> ( A. x ( x = A -> ph ) <-> ps ) ) |
|
4 | 2 3 | syl | |- ( ( F/ x ps /\ A. x ( x = A -> ( ph <-> ps ) ) /\ A e. V ) -> ( A. x ( x = A -> ph ) <-> ps ) ) |