ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  xpsnen GIF version

Theorem xpsnen 6683
Description: A set is equinumerous to its Cartesian product with a singleton. Proposition 4.22(c) of [Mendelson] p. 254. (Contributed by NM, 4-Jan-2004.) (Revised by Mario Carneiro, 15-Nov-2014.)
Hypotheses
Ref Expression
xpsnen.1 𝐴 ∈ V
xpsnen.2 𝐵 ∈ V
Assertion
Ref Expression
xpsnen (𝐴 × {𝐵}) ≈ 𝐴

Proof of Theorem xpsnen
Dummy variables 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 xpsnen.1 . . 3 𝐴 ∈ V
2 xpsnen.2 . . . 4 𝐵 ∈ V
32snex 4079 . . 3 {𝐵} ∈ V
41, 3xpex 4624 . 2 (𝐴 × {𝐵}) ∈ V
5 elxp 4526 . . 3 (𝑦 ∈ (𝐴 × {𝐵}) ↔ ∃𝑥𝑧(𝑦 = ⟨𝑥, 𝑧⟩ ∧ (𝑥𝐴𝑧 ∈ {𝐵})))
6 inteq 3744 . . . . . . . 8 (𝑦 = ⟨𝑥, 𝑧⟩ → 𝑦 = 𝑥, 𝑧⟩)
76inteqd 3746 . . . . . . 7 (𝑦 = ⟨𝑥, 𝑧⟩ → 𝑦 = 𝑥, 𝑧⟩)
8 vex 2663 . . . . . . . 8 𝑥 ∈ V
9 vex 2663 . . . . . . . 8 𝑧 ∈ V
108, 9op1stb 4369 . . . . . . 7 𝑥, 𝑧⟩ = 𝑥
117, 10syl6eq 2166 . . . . . 6 (𝑦 = ⟨𝑥, 𝑧⟩ → 𝑦 = 𝑥)
1211, 8syl6eqel 2208 . . . . 5 (𝑦 = ⟨𝑥, 𝑧⟩ → 𝑦 ∈ V)
1312adantr 274 . . . 4 ((𝑦 = ⟨𝑥, 𝑧⟩ ∧ (𝑥𝐴𝑧 ∈ {𝐵})) → 𝑦 ∈ V)
1413exlimivv 1852 . . 3 (∃𝑥𝑧(𝑦 = ⟨𝑥, 𝑧⟩ ∧ (𝑥𝐴𝑧 ∈ {𝐵})) → 𝑦 ∈ V)
155, 14sylbi 120 . 2 (𝑦 ∈ (𝐴 × {𝐵}) → 𝑦 ∈ V)
168, 2opex 4121 . . 3 𝑥, 𝐵⟩ ∈ V
1716a1i 9 . 2 (𝑥𝐴 → ⟨𝑥, 𝐵⟩ ∈ V)
18 eqvisset 2670 . . . . 5 (𝑥 = 𝑦 𝑦 ∈ V)
19 ancom 264 . . . . . . . . . . 11 (((𝑦 = ⟨𝑥, 𝑧⟩ ∧ 𝑥𝐴) ∧ 𝑧 ∈ {𝐵}) ↔ (𝑧 ∈ {𝐵} ∧ (𝑦 = ⟨𝑥, 𝑧⟩ ∧ 𝑥𝐴)))
20 anass 398 . . . . . . . . . . 11 (((𝑦 = ⟨𝑥, 𝑧⟩ ∧ 𝑥𝐴) ∧ 𝑧 ∈ {𝐵}) ↔ (𝑦 = ⟨𝑥, 𝑧⟩ ∧ (𝑥𝐴𝑧 ∈ {𝐵})))
21 velsn 3514 . . . . . . . . . . . 12 (𝑧 ∈ {𝐵} ↔ 𝑧 = 𝐵)
2221anbi1i 453 . . . . . . . . . . 11 ((𝑧 ∈ {𝐵} ∧ (𝑦 = ⟨𝑥, 𝑧⟩ ∧ 𝑥𝐴)) ↔ (𝑧 = 𝐵 ∧ (𝑦 = ⟨𝑥, 𝑧⟩ ∧ 𝑥𝐴)))
2319, 20, 223bitr3i 209 . . . . . . . . . 10 ((𝑦 = ⟨𝑥, 𝑧⟩ ∧ (𝑥𝐴𝑧 ∈ {𝐵})) ↔ (𝑧 = 𝐵 ∧ (𝑦 = ⟨𝑥, 𝑧⟩ ∧ 𝑥𝐴)))
2423exbii 1569 . . . . . . . . 9 (∃𝑧(𝑦 = ⟨𝑥, 𝑧⟩ ∧ (𝑥𝐴𝑧 ∈ {𝐵})) ↔ ∃𝑧(𝑧 = 𝐵 ∧ (𝑦 = ⟨𝑥, 𝑧⟩ ∧ 𝑥𝐴)))
25 opeq2 3676 . . . . . . . . . . . 12 (𝑧 = 𝐵 → ⟨𝑥, 𝑧⟩ = ⟨𝑥, 𝐵⟩)
2625eqeq2d 2129 . . . . . . . . . . 11 (𝑧 = 𝐵 → (𝑦 = ⟨𝑥, 𝑧⟩ ↔ 𝑦 = ⟨𝑥, 𝐵⟩))
2726anbi1d 460 . . . . . . . . . 10 (𝑧 = 𝐵 → ((𝑦 = ⟨𝑥, 𝑧⟩ ∧ 𝑥𝐴) ↔ (𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴)))
282, 27ceqsexv 2699 . . . . . . . . 9 (∃𝑧(𝑧 = 𝐵 ∧ (𝑦 = ⟨𝑥, 𝑧⟩ ∧ 𝑥𝐴)) ↔ (𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴))
29 inteq 3744 . . . . . . . . . . . . . 14 (𝑦 = ⟨𝑥, 𝐵⟩ → 𝑦 = 𝑥, 𝐵⟩)
3029inteqd 3746 . . . . . . . . . . . . 13 (𝑦 = ⟨𝑥, 𝐵⟩ → 𝑦 = 𝑥, 𝐵⟩)
318, 2op1stb 4369 . . . . . . . . . . . . 13 𝑥, 𝐵⟩ = 𝑥
3230, 31syl6req 2167 . . . . . . . . . . . 12 (𝑦 = ⟨𝑥, 𝐵⟩ → 𝑥 = 𝑦)
3332pm4.71ri 389 . . . . . . . . . . 11 (𝑦 = ⟨𝑥, 𝐵⟩ ↔ (𝑥 = 𝑦𝑦 = ⟨𝑥, 𝐵⟩))
3433anbi1i 453 . . . . . . . . . 10 ((𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴) ↔ ((𝑥 = 𝑦𝑦 = ⟨𝑥, 𝐵⟩) ∧ 𝑥𝐴))
35 anass 398 . . . . . . . . . 10 (((𝑥 = 𝑦𝑦 = ⟨𝑥, 𝐵⟩) ∧ 𝑥𝐴) ↔ (𝑥 = 𝑦 ∧ (𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴)))
3634, 35bitri 183 . . . . . . . . 9 ((𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴) ↔ (𝑥 = 𝑦 ∧ (𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴)))
3724, 28, 363bitri 205 . . . . . . . 8 (∃𝑧(𝑦 = ⟨𝑥, 𝑧⟩ ∧ (𝑥𝐴𝑧 ∈ {𝐵})) ↔ (𝑥 = 𝑦 ∧ (𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴)))
3837exbii 1569 . . . . . . 7 (∃𝑥𝑧(𝑦 = ⟨𝑥, 𝑧⟩ ∧ (𝑥𝐴𝑧 ∈ {𝐵})) ↔ ∃𝑥(𝑥 = 𝑦 ∧ (𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴)))
395, 38bitri 183 . . . . . 6 (𝑦 ∈ (𝐴 × {𝐵}) ↔ ∃𝑥(𝑥 = 𝑦 ∧ (𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴)))
40 opeq1 3675 . . . . . . . . 9 (𝑥 = 𝑦 → ⟨𝑥, 𝐵⟩ = ⟨ 𝑦, 𝐵⟩)
4140eqeq2d 2129 . . . . . . . 8 (𝑥 = 𝑦 → (𝑦 = ⟨𝑥, 𝐵⟩ ↔ 𝑦 = ⟨ 𝑦, 𝐵⟩))
42 eleq1 2180 . . . . . . . 8 (𝑥 = 𝑦 → (𝑥𝐴 𝑦𝐴))
4341, 42anbi12d 464 . . . . . . 7 (𝑥 = 𝑦 → ((𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴) ↔ (𝑦 = ⟨ 𝑦, 𝐵⟩ ∧ 𝑦𝐴)))
4443ceqsexgv 2788 . . . . . 6 ( 𝑦 ∈ V → (∃𝑥(𝑥 = 𝑦 ∧ (𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴)) ↔ (𝑦 = ⟨ 𝑦, 𝐵⟩ ∧ 𝑦𝐴)))
4539, 44syl5bb 191 . . . . 5 ( 𝑦 ∈ V → (𝑦 ∈ (𝐴 × {𝐵}) ↔ (𝑦 = ⟨ 𝑦, 𝐵⟩ ∧ 𝑦𝐴)))
4618, 45syl 14 . . . 4 (𝑥 = 𝑦 → (𝑦 ∈ (𝐴 × {𝐵}) ↔ (𝑦 = ⟨ 𝑦, 𝐵⟩ ∧ 𝑦𝐴)))
4746pm5.32ri 450 . . 3 ((𝑦 ∈ (𝐴 × {𝐵}) ∧ 𝑥 = 𝑦) ↔ ((𝑦 = ⟨ 𝑦, 𝐵⟩ ∧ 𝑦𝐴) ∧ 𝑥 = 𝑦))
4832adantr 274 . . . . 5 ((𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴) → 𝑥 = 𝑦)
4948pm4.71i 388 . . . 4 ((𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴) ↔ ((𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴) ∧ 𝑥 = 𝑦))
5043pm5.32ri 450 . . . 4 (((𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴) ∧ 𝑥 = 𝑦) ↔ ((𝑦 = ⟨ 𝑦, 𝐵⟩ ∧ 𝑦𝐴) ∧ 𝑥 = 𝑦))
5149, 50bitr2i 184 . . 3 (((𝑦 = ⟨ 𝑦, 𝐵⟩ ∧ 𝑦𝐴) ∧ 𝑥 = 𝑦) ↔ (𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴))
52 ancom 264 . . 3 ((𝑦 = ⟨𝑥, 𝐵⟩ ∧ 𝑥𝐴) ↔ (𝑥𝐴𝑦 = ⟨𝑥, 𝐵⟩))
5347, 51, 523bitri 205 . 2 ((𝑦 ∈ (𝐴 × {𝐵}) ∧ 𝑥 = 𝑦) ↔ (𝑥𝐴𝑦 = ⟨𝑥, 𝐵⟩))
544, 1, 15, 17, 53en2i 6632 1 (𝐴 × {𝐵}) ≈ 𝐴
Colors of variables: wff set class
Syntax hints:  wa 103  wb 104   = wceq 1316  wex 1453  wcel 1465  Vcvv 2660  {csn 3497  cop 3500   cint 3741   class class class wbr 3899   × cxp 4507  cen 6600
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 683  ax-5 1408  ax-7 1409  ax-gen 1410  ax-ie1 1454  ax-ie2 1455  ax-8 1467  ax-10 1468  ax-11 1469  ax-i12 1470  ax-bndl 1471  ax-4 1472  ax-13 1476  ax-14 1477  ax-17 1491  ax-i9 1495  ax-ial 1499  ax-i5r 1500  ax-ext 2099  ax-sep 4016  ax-pow 4068  ax-pr 4101  ax-un 4325
This theorem depends on definitions:  df-bi 116  df-3an 949  df-tru 1319  df-nf 1422  df-sb 1721  df-eu 1980  df-mo 1981  df-clab 2104  df-cleq 2110  df-clel 2113  df-nfc 2247  df-ral 2398  df-rex 2399  df-v 2662  df-un 3045  df-in 3047  df-ss 3054  df-pw 3482  df-sn 3503  df-pr 3504  df-op 3506  df-uni 3707  df-int 3742  df-br 3900  df-opab 3960  df-mpt 3961  df-id 4185  df-xp 4515  df-rel 4516  df-cnv 4517  df-co 4518  df-dm 4519  df-rn 4520  df-fun 5095  df-fn 5096  df-f 5097  df-f1 5098  df-fo 5099  df-f1o 5100  df-en 6603
This theorem is referenced by:  xpsneng  6684  endisj  6686
  Copyright terms: Public domain W3C validator