Theorem sbequ6 2497

Description: Substitution does not change a distinctor. Usage of this theorem is discouraged because it depends on ax-13 2403. (Contributed by NM, 5-Aug-1993.) (New usage is discouraged.)

Assertion

Ref	Expression
sbequ6	⊢ ([𝑤 / 𝑧] ¬ ∀𝑥 𝑥 = 𝑦 ↔ ¬ ∀𝑥 𝑥 = 𝑦)

Proof of Theorem sbequ6

Step	Hyp	Ref	Expression
1		nfnae 2465	. 2 ⊢ Ⅎ𝑧 ¬ ∀𝑥 𝑥 = 𝑦
2	1	sbf 2305	1 ⊢ ([𝑤 / 𝑧] ¬ ∀𝑥 𝑥 = 𝑦 ↔ ¬ ∀𝑥 𝑥 = 𝑦)

This proof depends on syntax axioms:  ¬ wn 3   ↔ wb 209  ∀wal 1567  [wsb 2095

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1824  ax-4 1838  ax-5 1939  ax-6 1996  ax-7 2037  ax-10 2175  ax-11 2191  ax-12 2212  ax-13 2403

This proof depends on definitions:  df-bi 210  df-an 401  df-or 861  df-tru 1572  df-ex 1809  df-nf 1813  df-sb 2096

This theorem is used by: (None)