Theorem nfdiOLD 2213

Description: Obsolete proof of nf5di 2105 as of 6-Oct-2021. (Contributed by NM, 17-Aug-2018.) (Proof shortened by Wolf Lammen, 10-Jul-2019.) (Proof modification is discouraged.) (New usage is discouraged.)

Hypothesis

Ref	Expression
nfdiOLD.1	⊢ (𝜑 → Ⅎ𝑥𝜑)

Assertion

Ref	Expression
nfdiOLD	⊢ Ⅎ𝑥𝜑

Proof of Theorem nfdiOLD

Step	Hyp	Ref	Expression
1		nfdiOLD.1	. . . 4 ⊢ (𝜑 → Ⅎ𝑥𝜑)
2	1	nfrdOLD 2178	. . 3 ⊢ (𝜑 → (𝜑 → ∀𝑥𝜑))
3	2	pm2.43i 50	. 2 ⊢ (𝜑 → ∀𝑥𝜑)
4	3	nfiOLD 1725	1 ⊢ Ⅎ𝑥𝜑

Syntax hints:   → wi 4  ∀wal 1473  ℲwnfOLD 1700

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-12 2034

This theorem depends on definitions:  df-bi 196  df-ex 1696  df-nfOLD 1712

This theorem is referenced by: (None)