Theorem nfa1-o 36908

Description: 𝑥 is not free in ∀𝑥𝜑. (Contributed by Mario Carneiro, 11-Aug-2016.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
nfa1-o	⊢ Ⅎ𝑥∀𝑥𝜑

Proof of Theorem nfa1-o

Step	Hyp	Ref	Expression
1		hba1-o 36890	. 2 ⊢ (∀𝑥𝜑 → ∀𝑥∀𝑥𝜑)
2	1	nf5i 2145	1 ⊢ Ⅎ𝑥∀𝑥𝜑

Syntax hints:  ∀wal 1539  Ⅎwnf 1789

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1801  ax-4 1815  ax-10 2140  ax-c5 36876  ax-c4 36877  ax-c7 36878

This theorem depends on definitions:  df-bi 206  df-ex 1786  df-nf 1790

This theorem is referenced by:  axc11n-16  36931  ax12eq  36934  ax12el  36935  ax12v2-o  36942