Description: Commuting conjunction in a biconditional. (Contributed by Peter Mazsa, 17-Jun-2018)
Ref | Expression | ||
---|---|---|---|
Hypothesis | biancomi.1 | |
|
Assertion | biancomi | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | biancomi.1 | |
|
2 | ancom | |
|
3 | 1 2 | bitr4i | |