Theorem nfaba1OLD

Description: Obsolete version of nfaba1 as of 14-May-2025. (Contributed by Mario Carneiro, 14-Oct-2016) (Revised by GG, 20-Jan-2024) (Proof modification is discouraged.) (New usage is discouraged.)

	Ref	Expression
Assertion	nfaba1OLD	⊢ Ⅎ 𝑥 { 𝑦 ∣ ∀ 𝑥 𝜑 }

Proof

Step	Hyp	Ref	Expression
1		nfa1	⊢ Ⅎ 𝑥 ∀ 𝑥 𝜑
2	1	nfab	⊢ Ⅎ 𝑥 { 𝑦 ∣ ∀ 𝑥 𝜑 }