Description: Alternate proof of bj-ceqsalgv . (Contributed by BJ, 12-Oct-2019) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypotheses | bj-ceqsalgv.1 | |- F/ x ps |
|
bj-ceqsalgv.2 | |- ( x = A -> ( ph <-> ps ) ) |
||
Assertion | bj-ceqsalgvALT | |- ( A e. V -> ( A. x ( x = A -> ph ) <-> ps ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | bj-ceqsalgv.1 | |- F/ x ps |
|
2 | bj-ceqsalgv.2 | |- ( x = A -> ( ph <-> ps ) ) |
|
3 | 2 | ax-gen | |- A. x ( x = A -> ( ph <-> ps ) ) |
4 | bj-ceqsaltv | |- ( ( F/ x ps /\ A. x ( x = A -> ( ph <-> ps ) ) /\ A e. V ) -> ( A. x ( x = A -> ph ) <-> ps ) ) |
|
5 | 1 3 4 | mp3an12 | |- ( A e. V -> ( A. x ( x = A -> ph ) <-> ps ) ) |