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Theorem spc2ed 28484
Description: Existential specialization with 2 quantifiers, using implicit substitution. (Contributed by Thierry Arnoux, 23-Aug-2017.)
Hypotheses
Ref Expression
spc2ed.x 𝑥𝜒
spc2ed.y 𝑦𝜒
spc2ed.1 ((𝜑 ∧ (𝑥 = 𝐴𝑦 = 𝐵)) → (𝜓𝜒))
Assertion
Ref Expression
spc2ed ((𝜑 ∧ (𝐴𝑉𝐵𝑊)) → (𝜒 → ∃𝑥𝑦𝜓))
Distinct variable groups:   𝑥,𝑦,𝐴   𝑥,𝐵,𝑦   𝜑,𝑥,𝑦
Allowed substitution hints:   𝜓(𝑥,𝑦)   𝜒(𝑥,𝑦)   𝑉(𝑥,𝑦)   𝑊(𝑥,𝑦)

Proof of Theorem spc2ed
StepHypRef Expression
1 elisset 3092 . . . 4 (𝐴𝑉 → ∃𝑥 𝑥 = 𝐴)
2 elisset 3092 . . . 4 (𝐵𝑊 → ∃𝑦 𝑦 = 𝐵)
31, 2anim12i 587 . . 3 ((𝐴𝑉𝐵𝑊) → (∃𝑥 𝑥 = 𝐴 ∧ ∃𝑦 𝑦 = 𝐵))
4 eeanv 2125 . . 3 (∃𝑥𝑦(𝑥 = 𝐴𝑦 = 𝐵) ↔ (∃𝑥 𝑥 = 𝐴 ∧ ∃𝑦 𝑦 = 𝐵))
53, 4sylibr 222 . 2 ((𝐴𝑉𝐵𝑊) → ∃𝑥𝑦(𝑥 = 𝐴𝑦 = 𝐵))
6 nfv 1796 . . . . 5 𝑥𝜑
7 spc2ed.x . . . . 5 𝑥𝜒
86, 7nfan 2059 . . . 4 𝑥(𝜑𝜒)
9 nfv 1796 . . . . . 6 𝑦𝜑
10 spc2ed.y . . . . . 6 𝑦𝜒
119, 10nfan 2059 . . . . 5 𝑦(𝜑𝜒)
12 anass 678 . . . . . . . 8 (((𝜒𝜑) ∧ (𝑥 = 𝐴𝑦 = 𝐵)) ↔ (𝜒 ∧ (𝜑 ∧ (𝑥 = 𝐴𝑦 = 𝐵))))
13 ancom 464 . . . . . . . . 9 ((𝜒𝜑) ↔ (𝜑𝜒))
1413anbi1i 726 . . . . . . . 8 (((𝜒𝜑) ∧ (𝑥 = 𝐴𝑦 = 𝐵)) ↔ ((𝜑𝜒) ∧ (𝑥 = 𝐴𝑦 = 𝐵)))
1512, 14bitr3i 264 . . . . . . 7 ((𝜒 ∧ (𝜑 ∧ (𝑥 = 𝐴𝑦 = 𝐵))) ↔ ((𝜑𝜒) ∧ (𝑥 = 𝐴𝑦 = 𝐵)))
16 spc2ed.1 . . . . . . . 8 ((𝜑 ∧ (𝑥 = 𝐴𝑦 = 𝐵)) → (𝜓𝜒))
1716biimparc 502 . . . . . . 7 ((𝜒 ∧ (𝜑 ∧ (𝑥 = 𝐴𝑦 = 𝐵))) → 𝜓)
1815, 17sylbir 223 . . . . . 6 (((𝜑𝜒) ∧ (𝑥 = 𝐴𝑦 = 𝐵)) → 𝜓)
1918ex 448 . . . . 5 ((𝜑𝜒) → ((𝑥 = 𝐴𝑦 = 𝐵) → 𝜓))
2011, 19eximd 2013 . . . 4 ((𝜑𝜒) → (∃𝑦(𝑥 = 𝐴𝑦 = 𝐵) → ∃𝑦𝜓))
218, 20eximd 2013 . . 3 ((𝜑𝜒) → (∃𝑥𝑦(𝑥 = 𝐴𝑦 = 𝐵) → ∃𝑥𝑦𝜓))
2221impancom 454 . 2 ((𝜑 ∧ ∃𝑥𝑦(𝑥 = 𝐴𝑦 = 𝐵)) → (𝜒 → ∃𝑥𝑦𝜓))
235, 22sylan2 489 1 ((𝜑 ∧ (𝐴𝑉𝐵𝑊)) → (𝜒 → ∃𝑥𝑦𝜓))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 194  wa 382   = wceq 1474  wex 1694  wnf 1698  wcel 1938
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1700  ax-4 1713  ax-5 1793  ax-6 1838  ax-7 1885  ax-10 1966  ax-11 1971  ax-12 1983  ax-ext 2494
This theorem depends on definitions:  df-bi 195  df-an 384  df-tru 1477  df-ex 1695  df-nf 1699  df-sb 1831  df-clab 2501  df-cleq 2507  df-clel 2510  df-v 3079
This theorem is referenced by:  spc2d  28485  cnvoprab  28674
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