Description: Equality theorem for class substitution. (Contributed by Thierry Arnoux, 4-Sep-2018)
Ref | Expression | ||
---|---|---|---|
Hypotheses | sbceqbid.1 | |
|
sbceqbid.2 | |
||
Assertion | sbceqbid | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sbceqbid.1 | |
|
2 | sbceqbid.2 | |
|
3 | 2 | abbidv | |
4 | 1 3 | eleq12d | |
5 | df-sbc | |
|
6 | df-sbc | |
|
7 | 4 5 6 | 3bitr4g | |