Description: Obsolete version of eubii as of 27-Sep-2023. (Contributed by NM, 9-Jul-1994) (Revised by Mario Carneiro, 6-Oct-2016) (Proof modification is discouraged.) (New usage is discouraged.)
Ref | Expression | ||
---|---|---|---|
Hypothesis | eubii.1 | |- ( ph <-> ps ) |
|
Assertion | eubiiOLD | |- ( E! x ph <-> E! x ps ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eubii.1 | |- ( ph <-> ps ) |
|
2 | eubi | |- ( A. x ( ph <-> ps ) -> ( E! x ph <-> E! x ps ) ) |
|
3 | 2 1 | mpg | |- ( E! x ph <-> E! x ps ) |