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 → ∀ 𝑥 𝜓 )
Assertion	19.21bi	⊢ ( 𝜑 → 𝜓 )

Proof

Step	Hyp	Ref	Expression
1		19.21bi.1	⊢ ( 𝜑 → ∀ 𝑥 𝜓 )
2		sp	⊢ ( ∀ 𝑥 𝜓 → 𝜓 )
3	1 2	syl	⊢ ( 𝜑 → 𝜓 )