Theorem aevdemo 30848

Description: Proof illustrating the comment of aev2 2093. (Contributed by BJ, 30-Mar-2021.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
aevdemo	⊢ (∀𝑥 𝑥 = 𝑦 → ((∃𝑎∀𝑏 𝑐 = 𝑑 ∨ ∃𝑒 𝑓 = 𝑔) ∧ ∀ℎ(𝑖 = 𝑗 → 𝑘 = 𝑙)))

Distinct variable group:   𝑥,𝑦

Proof of Theorem aevdemo

Dummy variables 𝑚 𝑛 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		aev 2092	. . . 4 ⊢ (∀𝑥 𝑥 = 𝑦 → ∀𝑒 𝑓 = 𝑔)
2	1	19.2d 2010	. . 3 ⊢ (∀𝑥 𝑥 = 𝑦 → ∃𝑒 𝑓 = 𝑔)
3	2	olcd 888	. 2 ⊢ (∀𝑥 𝑥 = 𝑦 → (∃𝑎∀𝑏 𝑐 = 𝑑 ∨ ∃𝑒 𝑓 = 𝑔))
4		aev 2092	. . 3 ⊢ (∀𝑥 𝑥 = 𝑦 → ∀𝑚 𝑚 = 𝑛)
5		aeveq 2091	. . . . 5 ⊢ (∀𝑚 𝑚 = 𝑛 → 𝑘 = 𝑙)
6	5	a1d 26	. . . 4 ⊢ (∀𝑚 𝑚 = 𝑛 → (𝑖 = 𝑗 → 𝑘 = 𝑙))
7	6	alrimiv 1960	. . 3 ⊢ (∀𝑚 𝑚 = 𝑛 → ∀ℎ(𝑖 = 𝑗 → 𝑘 = 𝑙))
8	4, 7	syl 18	. 2 ⊢ (∀𝑥 𝑥 = 𝑦 → ∀ℎ(𝑖 = 𝑗 → 𝑘 = 𝑙))
9	3, 8	jca 521	1 ⊢ (∀𝑥 𝑥 = 𝑦 → ((∃𝑎∀𝑏 𝑐 = 𝑑 ∨ ∃𝑒 𝑓 = 𝑔) ∧ ∀ℎ(𝑖 = 𝑗 → 𝑘 = 𝑙)))

This proof depends on syntax axioms:   → wi 4   ∧ wa 401   ∨ wo 861  ∀wal 1568  ∃wex 1812

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

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-ex 1813

This theorem is used by: (None)