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Metamath Proof Explorer

Theorem 2a1i

Description: Inference introducing two antecedents. Two applications of a1i . Inference associated with 2a1 . (Contributed by Jeff Hankins, 4-Aug-2009)

		Ref	Expression
	Hypothesis	2a1i.1	$⊢ φ$
	Assertion	2a1i	$⊢ ψ \to (χ \to φ)$

Proof

Step	Hyp	Ref	Expression
1		2a1i.1	$⊢ φ$
2	1	a1i	$⊢ χ \to φ$
3	2	a1i	$⊢ ψ \to (χ \to φ)$