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Metamath Proof Explorer

Theorem 19.21bi

Description: Inference form of 19.21 and also deduction form of sp . (Contributed by NM, 26-May-1993)

		Ref	Expression
	Hypothesis	19.21bi.1	$⊢ φ \to \forall x ψ$
	Assertion	19.21bi	$⊢ φ \to ψ$

Step	Hyp	Ref	Expression
1		19.21bi.1	$⊢ φ \to \forall x ψ$
2		sp	$⊢ \forall x ψ \to ψ$
3	1 2	syl	$⊢ φ \to ψ$