Description: Elementhood in the class of functions. (Contributed by Peter Mazsa, 24-Jul-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | elfunsALTV | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dffunsALTV | |
|
2 | cosseq | |
|
3 | 2 | eleq1d | |
4 | 1 3 | rabeqel | |