Theorem 2ax6eOLD 2495

Description: Obsolete version of 2ax6e 2494 as of 3-Oct-2023. (Contributed by Wolf Lammen, 28-Sep-2018.) (Proof modification is discouraged.) (New usage is discouraged.)

Assertion

Ref	Expression
2ax6eOLD	⊢ ∃𝑧∃𝑤(𝑧 = 𝑥 ∧ 𝑤 = 𝑦)

Distinct variable group:   𝑧,𝑤

Proof of Theorem 2ax6eOLD

Step	Hyp	Ref	Expression
1		aeveq 2061	. . . 4 ⊢ (∀𝑤 𝑤 = 𝑧 → 𝑧 = 𝑥)
2		aeveq 2061	. . . 4 ⊢ (∀𝑤 𝑤 = 𝑧 → 𝑤 = 𝑦)
3	1, 2	jca 514	. . 3 ⊢ (∀𝑤 𝑤 = 𝑧 → (𝑧 = 𝑥 ∧ 𝑤 = 𝑦))
4		19.8a 2180	. . 3 ⊢ ((𝑧 = 𝑥 ∧ 𝑤 = 𝑦) → ∃𝑤(𝑧 = 𝑥 ∧ 𝑤 = 𝑦))
5		19.8a 2180	. . 3 ⊢ (∃𝑤(𝑧 = 𝑥 ∧ 𝑤 = 𝑦) → ∃𝑧∃𝑤(𝑧 = 𝑥 ∧ 𝑤 = 𝑦))
6	3, 4, 5	3syl 18	. 2 ⊢ (∀𝑤 𝑤 = 𝑧 → ∃𝑧∃𝑤(𝑧 = 𝑥 ∧ 𝑤 = 𝑦))
7		2ax6elem 2493	. 2 ⊢ (¬ ∀𝑤 𝑤 = 𝑧 → ∃𝑧∃𝑤(𝑧 = 𝑥 ∧ 𝑤 = 𝑦))
8	6, 7	pm2.61i 184	1 ⊢ ∃𝑧∃𝑤(𝑧 = 𝑥 ∧ 𝑤 = 𝑦)

Syntax hints:   ∧ wa 398  ∀wal 1535  ∃wex 1780

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1970  ax-7 2015  ax-10 2145  ax-11 2161  ax-12 2177  ax-13 2390

This theorem depends on definitions:  df-bi 209  df-an 399  df-or 844  df-tru 1540  df-ex 1781  df-nf 1785

This theorem is referenced by: (None)