Theorem reuprg 4639

Description: Convert a restricted existential uniqueness over a pair to a disjunction and an implication . (Contributed by AV, 2-Apr-2023.)

Hypotheses

Ref	Expression
reuprg.1	⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜓))
reuprg.2	⊢ (𝑥 = 𝐵 → (𝜑 ↔ 𝜒))

Assertion

Ref	Expression
reuprg	⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (∃!𝑥 ∈ {𝐴, 𝐵}𝜑 ↔ ((𝜓 ∨ 𝜒) ∧ ((𝜒 ∧ 𝜓) → 𝐴 = 𝐵))))

Distinct variable groups:   𝑥,𝐴   𝑥,𝐵   𝜓,𝑥   𝜒,𝑥

Allowed substitution hints:   𝜑(𝑥)   𝑉(𝑥)   𝑊(𝑥)

Proof of Theorem reuprg

Step	Hyp	Ref	Expression
1		reuprg.1	. . 3 ⊢ (𝑥 = 𝐴 → (𝜑 ↔ 𝜓))
2		reuprg.2	. . 3 ⊢ (𝑥 = 𝐵 → (𝜑 ↔ 𝜒))
3	1, 2	reuprg0 4638	. 2 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (∃!𝑥 ∈ {𝐴, 𝐵}𝜑 ↔ ((𝜓 ∧ (𝜒 → 𝐴 = 𝐵)) ∨ (𝜒 ∧ (𝜓 → 𝐴 = 𝐵)))))
4		orddi 1006	. . 3 ⊢ (((𝜓 ∧ (𝜒 → 𝐴 = 𝐵)) ∨ (𝜒 ∧ (𝜓 → 𝐴 = 𝐵))) ↔ (((𝜓 ∨ 𝜒) ∧ (𝜓 ∨ (𝜓 → 𝐴 = 𝐵))) ∧ (((𝜒 → 𝐴 = 𝐵) ∨ 𝜒) ∧ ((𝜒 → 𝐴 = 𝐵) ∨ (𝜓 → 𝐴 = 𝐵)))))
5		curryax 890	. . . . . 6 ⊢ (𝜓 ∨ (𝜓 → 𝐴 = 𝐵))
6	5	biantru 532	. . . . 5 ⊢ ((𝜓 ∨ 𝜒) ↔ ((𝜓 ∨ 𝜒) ∧ (𝜓 ∨ (𝜓 → 𝐴 = 𝐵))))
7	6	bicomi 226	. . . 4 ⊢ (((𝜓 ∨ 𝜒) ∧ (𝜓 ∨ (𝜓 → 𝐴 = 𝐵))) ↔ (𝜓 ∨ 𝜒))
8		curryax 890	. . . . . . . 8 ⊢ (𝜒 ∨ (𝜒 → 𝐴 = 𝐵))
9		orcom 866	. . . . . . . 8 ⊢ (((𝜒 → 𝐴 = 𝐵) ∨ 𝜒) ↔ (𝜒 ∨ (𝜒 → 𝐴 = 𝐵)))
10	8, 9	mpbir 233	. . . . . . 7 ⊢ ((𝜒 → 𝐴 = 𝐵) ∨ 𝜒)
11	10	biantrur 533	. . . . . 6 ⊢ (((𝜒 → 𝐴 = 𝐵) ∨ (𝜓 → 𝐴 = 𝐵)) ↔ (((𝜒 → 𝐴 = 𝐵) ∨ 𝜒) ∧ ((𝜒 → 𝐴 = 𝐵) ∨ (𝜓 → 𝐴 = 𝐵))))
12	11	bicomi 226	. . . . 5 ⊢ ((((𝜒 → 𝐴 = 𝐵) ∨ 𝜒) ∧ ((𝜒 → 𝐴 = 𝐵) ∨ (𝜓 → 𝐴 = 𝐵))) ↔ ((𝜒 → 𝐴 = 𝐵) ∨ (𝜓 → 𝐴 = 𝐵)))
13		pm4.79 1000	. . . . 5 ⊢ (((𝜒 → 𝐴 = 𝐵) ∨ (𝜓 → 𝐴 = 𝐵)) ↔ ((𝜒 ∧ 𝜓) → 𝐴 = 𝐵))
14	12, 13	bitri 277	. . . 4 ⊢ ((((𝜒 → 𝐴 = 𝐵) ∨ 𝜒) ∧ ((𝜒 → 𝐴 = 𝐵) ∨ (𝜓 → 𝐴 = 𝐵))) ↔ ((𝜒 ∧ 𝜓) → 𝐴 = 𝐵))
15	7, 14	anbi12i 628	. . 3 ⊢ ((((𝜓 ∨ 𝜒) ∧ (𝜓 ∨ (𝜓 → 𝐴 = 𝐵))) ∧ (((𝜒 → 𝐴 = 𝐵) ∨ 𝜒) ∧ ((𝜒 → 𝐴 = 𝐵) ∨ (𝜓 → 𝐴 = 𝐵)))) ↔ ((𝜓 ∨ 𝜒) ∧ ((𝜒 ∧ 𝜓) → 𝐴 = 𝐵)))
16	4, 15	bitri 277	. 2 ⊢ (((𝜓 ∧ (𝜒 → 𝐴 = 𝐵)) ∨ (𝜒 ∧ (𝜓 → 𝐴 = 𝐵))) ↔ ((𝜓 ∨ 𝜒) ∧ ((𝜒 ∧ 𝜓) → 𝐴 = 𝐵)))
17	3, 16	syl6bb 289	1 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (∃!𝑥 ∈ {𝐴, 𝐵}𝜑 ↔ ((𝜓 ∨ 𝜒) ∧ ((𝜒 ∧ 𝜓) → 𝐴 = 𝐵))))

Syntax hints:   → wi 4   ↔ wb 208   ∧ wa 398   ∨ wo 843   = wceq 1537   ∈ wcel 2114  ∃!wreu 3140  {cpr 4569

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-8 2116  ax-9 2124  ax-10 2145  ax-11 2161  ax-12 2177  ax-ext 2793

This theorem depends on definitions:  df-bi 209  df-an 399  df-or 844  df-3an 1085  df-tru 1540  df-ex 1781  df-nf 1785  df-sb 2070  df-mo 2622  df-eu 2654  df-clab 2800  df-cleq 2814  df-clel 2893  df-nfc 2963  df-ral 3143  df-rex 3144  df-reu 3145  df-v 3496  df-sbc 3773  df-un 3941  df-sn 4568  df-pr 4570

This theorem is referenced by:  reurexprg  4640