Description: New way ( elv , and the theorems beginning with "el2v" or "el3v") to shorten some proofs. (Contributed by Peter Mazsa, 16-Oct-2020)
Ref | Expression | ||
---|---|---|---|
Hypothesis | el3v2.1 | |- ( ( ph /\ y e. _V /\ ch ) -> th ) |
|
Assertion | el3v2 | |- ( ( ph /\ ch ) -> th ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | el3v2.1 | |- ( ( ph /\ y e. _V /\ ch ) -> th ) |
|
2 | vex | |- y e. _V |
|
3 | 2 1 | mp3an2 | |- ( ( ph /\ ch ) -> th ) |