Description: Equivalent wff's yield equal restricted class abstractions. (Contributed by Thierry Arnoux, 4-Feb-2017)
Ref | Expression | ||
---|---|---|---|
Hypothesis | rabbidva2.1 | |
|
Assertion | rabbidva2 | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | rabbidva2.1 | |
|
2 | 1 | abbidv | |
3 | df-rab | |
|
4 | df-rab | |
|
5 | 2 3 4 | 3eqtr4g | |