Metamath Proof Explorer


Theorem pm5.44

Description: Theorem *5.44 of WhiteheadRussell p. 125. (Contributed by NM, 3-Jan-2005)

Ref Expression
Assertion pm5.44 φ ψ φ χ φ ψ χ

Proof

Step Hyp Ref Expression
1 jcab φ ψ χ φ ψ φ χ
2 1 baibr φ ψ φ χ φ ψ χ