Metamath Proof Explorer


Theorem biancomi

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

Ref Expression
Hypothesis biancomi.1 φ χ ψ
Assertion biancomi φ ψ χ

Proof

Step Hyp Ref Expression
1 biancomi.1 φ χ ψ
2 ancom ψ χ χ ψ
3 1 2 bitr4i φ ψ χ