Metamath Proof Explorer


Theorem pm5.32ri

Description: Distribution of implication over biconditional (inference form). (Contributed by NM, 12-Mar-1995)

Ref Expression
Hypothesis pm5.32i.1 φ ψ χ
Assertion pm5.32ri ψ φ χ φ

Proof

Step Hyp Ref Expression
1 pm5.32i.1 φ ψ χ
2 1 pm5.32i φ ψ φ χ
3 ancom ψ φ φ ψ
4 ancom χ φ φ χ
5 2 3 4 3bitr4i ψ φ χ φ