Description: Distributive law for converse over intersection. Theorem 15 of Suppes p. 62. (Contributed by NM, 25-Mar-1998) (Revised by Mario Carneiro, 26-Jun-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | cnvin | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cnvdif | |
|
2 | cnvdif | |
|
3 | 2 | difeq2i | |
4 | 1 3 | eqtri | |
5 | dfin4 | |
|
6 | 5 | cnveqi | |
7 | dfin4 | |
|
8 | 4 6 7 | 3eqtr4i | |