This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.

Metamath Proof Explorer

Theorem pm3.3

Description: Theorem *3.3 (Exp) of WhiteheadRussell p. 112. (Contributed by NM, 3-Jan-2005) (Proof shortened by Wolf Lammen, 24-Mar-2013)

		Ref	Expression
	Assertion	pm3.3	$⊢ ((φ \land ψ) \to χ) \to (φ \to (ψ \to χ))$

Step	Hyp	Ref	Expression
1		id	$⊢ ((φ \land ψ) \to χ) \to ((φ \land ψ) \to χ)$
2	1	expd	$⊢ ((φ \land ψ) \to χ) \to (φ \to (ψ \to χ))$