Theorem ax11-pm 37508

Description: Proof of ax-11 2195 similar to PM's proof of alcom 2197 (PM*11.2). For a proof closer to PM's proof, see ax11-pm2 37512. Axiom ax-11 2195 is used in the proof only through nfa2 2213. (Contributed by BJ, 15-Sep-2018.) (Proof modification is discouraged.)

Assertion

Ref	Expression
ax11-pm	⊢ (∀𝑥∀𝑦𝜑 → ∀𝑦∀𝑥𝜑)

Proof of Theorem ax11-pm

Step	Hyp	Ref	Expression
1		2sp 2225	. . 3 ⊢ (∀𝑥∀𝑦𝜑 → 𝜑)
2	1	gen2 1829	. 2 ⊢ ∀𝑦∀𝑥(∀𝑥∀𝑦𝜑 → 𝜑)
3		nfa2 2213	. . 3 ⊢ Ⅎ𝑦∀𝑥∀𝑦𝜑
4		nfa1 2189	. . 3 ⊢ Ⅎ𝑥∀𝑥∀𝑦𝜑
5	3, 4	2stdpc5 37505	. 2 ⊢ (∀𝑦∀𝑥(∀𝑥∀𝑦𝜑 → 𝜑) → (∀𝑥∀𝑦𝜑 → ∀𝑦∀𝑥𝜑))
6	2, 5	ax-mp 5	1 ⊢ (∀𝑥∀𝑦𝜑 → ∀𝑦∀𝑥𝜑)

This proof depends on syntax axioms:   → wi 4  ∀wal 1568

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-10 2179  ax-11 2195  ax-12 2216

This proof depends on definitions:  df-bi 210  df-or 862  df-ex 1813  df-nf 1817

This theorem is used by: (None)