Description: Version of 19.8a with a disjoint variable condition, requiring fewer axioms. Converse of ax5e . (Contributed by BJ, 12-Mar-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | 19.8v | |- ( ph -> E. x ph ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ax-5 | |- ( ph -> A. x ph ) |
|
2 | 1 | 19.8w | |- ( ph -> E. x ph ) |