Theorem wl-ax11-lem5 33496

Description: Lemma. (Contributed by Wolf Lammen, 30-Jun-2019.)

Assertion

Ref	Expression
wl-ax11-lem5	⊢ (∀𝑢 𝑢 = 𝑦 → (∀𝑢[𝑢 / 𝑦]𝜑 ↔ ∀𝑦𝜑))

Proof of Theorem wl-ax11-lem5

Step	Hyp	Ref	Expression
1		sbequ12r 2150	. . 3 ⊢ (𝑢 = 𝑦 → ([𝑢 / 𝑦]𝜑 ↔ 𝜑))
2	1	sps 2093	. 2 ⊢ (∀𝑢 𝑢 = 𝑦 → ([𝑢 / 𝑦]𝜑 ↔ 𝜑))
3	2	dral1 2356	1 ⊢ (∀𝑢 𝑢 = 𝑦 → (∀𝑢[𝑢 / 𝑦]𝜑 ↔ ∀𝑦𝜑))

Syntax hints:   → wi 4   ↔ wb 196  ∀wal 1521  [wsb 1937

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1762  ax-4 1777  ax-5 1879  ax-6 1945  ax-7 1981  ax-10 2059  ax-12 2087  ax-13 2282

This theorem depends on definitions:  df-bi 197  df-or 384  df-an 385  df-ex 1745  df-nf 1750  df-sb 1938

This theorem is referenced by:  wl-ax11-lem6  33497