Description: Conjoin both sides of two equivalences. (Contributed by NM, 12-Mar-1993)
Ref | Expression | ||
---|---|---|---|
Hypotheses | anbi12.1 | |
|
anbi12.2 | |
||
Assertion | anbi12i | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | anbi12.1 | |
|
2 | anbi12.2 | |
|
3 | 1 | anbi1i | |
4 | 2 | anbi2i | |
5 | 3 4 | bitri | |