Description: Nonfreeness implies the equivalent of ax5ea . (Contributed by BJ, 28-Jul-2023)
Ref | Expression | ||
---|---|---|---|
Assertion | bj-nnfea | |- ( F// x ph -> ( E. x ph -> A. x ph ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | bj-nnfe | |- ( F// x ph -> ( E. x ph -> ph ) ) |
|
2 | bj-nnfa | |- ( F// x ph -> ( ph -> A. x ph ) ) |
|
3 | 1 2 | syld | |- ( F// x ph -> ( E. x ph -> A. x ph ) ) |