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

Metamath Proof Explorer

Theorem pm5.35

Description: Theorem *5.35 of WhiteheadRussell p. 125. Closed form of 2thd . (Contributed by NM, 3-Jan-2005)

		Ref	Expression
	Assertion	pm5.35	$⊢ ((φ \to ψ) \land (φ \to χ)) \to (φ \to (ψ \leftrightarrow χ))$

Step	Hyp	Ref	Expression
1		pm5.1	$⊢ ((φ \to ψ) \land (φ \to χ)) \to ((φ \to ψ) \leftrightarrow (φ \to χ))$
2	1	pm5.74rd	$⊢ ((φ \to ψ) \land (φ \to χ)) \to (φ \to (ψ \leftrightarrow χ))$