Metamath Proof Explorer


Theorem biancomi

Description: Commuting conjunction in a biconditional. (Contributed by Peter Mazsa, 17-Jun-2018)

Ref Expression
Hypothesis biancomi.1 φχψ
Assertion biancomi φψχ

Proof

Step Hyp Ref Expression
1 biancomi.1 φχψ
2 ancom ψχχψ
3 1 2 bitr4i φψχ