Metamath Proof Explorer


Theorem pm3.41

Description: Theorem *3.41 of WhiteheadRussell p. 113. (Contributed by NM, 3-Jan-2005)

Ref Expression
Assertion pm3.41 φ χ φ ψ χ

Proof

Step Hyp Ref Expression
1 simpl φ ψ φ
2 1 imim1i φ χ φ ψ χ