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Metamath Proof Explorer

Theorem axc4i

Description: Inference version of axc4 . (Contributed by NM, 3-Jan-1993)

		Ref	Expression
	Hypothesis	axc4i.1	$⊢ \forall x φ \to ψ$
	Assertion	axc4i	$⊢ \forall x φ \to \forall x ψ$

Step	Hyp	Ref	Expression
1		axc4i.1	$⊢ \forall x φ \to ψ$
2		nfa1	$⊢ Ⅎ x \forall x φ$
3	2 1	alrimi	$⊢ \forall x φ \to \forall x ψ$