Description: Equality theorem for converse relation. (Contributed by NM, 13-Aug-1995)
Ref | Expression | ||
---|---|---|---|
Assertion | cnveq | |- ( A = B -> `' A = `' B ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cnvss | |- ( A C_ B -> `' A C_ `' B ) |
|
2 | cnvss | |- ( B C_ A -> `' B C_ `' A ) |
|
3 | 1 2 | anim12i | |- ( ( A C_ B /\ B C_ A ) -> ( `' A C_ `' B /\ `' B C_ `' A ) ) |
4 | eqss | |- ( A = B <-> ( A C_ B /\ B C_ A ) ) |
|
5 | eqss | |- ( `' A = `' B <-> ( `' A C_ `' B /\ `' B C_ `' A ) ) |
|
6 | 3 4 5 | 3imtr4i | |- ( A = B -> `' A = `' B ) |