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Theorem fphpd 39687
 Description: Pigeonhole principle expressed with implicit substitution. If the range is smaller than the domain, two inputs must be mapped to the same output. (Contributed by Stefan O'Rear, 19-Oct-2014.) (Revised by Stefan O'Rear, 6-May-2015.)
Hypotheses
Ref Expression
fphpd.a (𝜑𝐵𝐴)
fphpd.b ((𝜑𝑥𝐴) → 𝐶𝐵)
fphpd.c (𝑥 = 𝑦𝐶 = 𝐷)
Assertion
Ref Expression
fphpd (𝜑 → ∃𝑥𝐴𝑦𝐴 (𝑥𝑦𝐶 = 𝐷))
Distinct variable groups:   𝑥,𝐴,𝑦   𝑥,𝐵,𝑦   𝑦,𝐶   𝑥,𝐷   𝜑,𝑥,𝑦
Allowed substitution hints:   𝐶(𝑥)   𝐷(𝑦)

Proof of Theorem fphpd
Dummy variables 𝑎 𝑏 are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 domnsym 8631 . . . 4 (𝐴𝐵 → ¬ 𝐵𝐴)
2 fphpd.a . . . 4 (𝜑𝐵𝐴)
31, 2nsyl3 140 . . 3 (𝜑 → ¬ 𝐴𝐵)
4 relsdom 8503 . . . . . . 7 Rel ≺
54brrelex1i 5585 . . . . . 6 (𝐵𝐴𝐵 ∈ V)
62, 5syl 17 . . . . 5 (𝜑𝐵 ∈ V)
76adantr 484 . . . 4 ((𝜑 ∧ ∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦)) → 𝐵 ∈ V)
8 nfv 1915 . . . . . . . . 9 𝑥(𝜑𝑎𝐴)
9 nfcsb1v 3879 . . . . . . . . . 10 𝑥𝑎 / 𝑥𝐶
109nfel1 2995 . . . . . . . . 9 𝑥𝑎 / 𝑥𝐶𝐵
118, 10nfim 1897 . . . . . . . 8 𝑥((𝜑𝑎𝐴) → 𝑎 / 𝑥𝐶𝐵)
12 eleq1w 2896 . . . . . . . . . 10 (𝑥 = 𝑎 → (𝑥𝐴𝑎𝐴))
1312anbi2d 631 . . . . . . . . 9 (𝑥 = 𝑎 → ((𝜑𝑥𝐴) ↔ (𝜑𝑎𝐴)))
14 csbeq1a 3869 . . . . . . . . . 10 (𝑥 = 𝑎𝐶 = 𝑎 / 𝑥𝐶)
1514eleq1d 2898 . . . . . . . . 9 (𝑥 = 𝑎 → (𝐶𝐵𝑎 / 𝑥𝐶𝐵))
1613, 15imbi12d 348 . . . . . . . 8 (𝑥 = 𝑎 → (((𝜑𝑥𝐴) → 𝐶𝐵) ↔ ((𝜑𝑎𝐴) → 𝑎 / 𝑥𝐶𝐵)))
17 fphpd.b . . . . . . . 8 ((𝜑𝑥𝐴) → 𝐶𝐵)
1811, 16, 17chvarfv 2243 . . . . . . 7 ((𝜑𝑎𝐴) → 𝑎 / 𝑥𝐶𝐵)
1918ex 416 . . . . . 6 (𝜑 → (𝑎𝐴𝑎 / 𝑥𝐶𝐵))
2019adantr 484 . . . . 5 ((𝜑 ∧ ∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦)) → (𝑎𝐴𝑎 / 𝑥𝐶𝐵))
21 csbid 3868 . . . . . . . . . . 11 𝑥 / 𝑥𝐶 = 𝐶
22 vex 3472 . . . . . . . . . . . 12 𝑦 ∈ V
23 fphpd.c . . . . . . . . . . . 12 (𝑥 = 𝑦𝐶 = 𝐷)
2422, 23csbie 3890 . . . . . . . . . . 11 𝑦 / 𝑥𝐶 = 𝐷
2521, 24eqeq12i 2837 . . . . . . . . . 10 (𝑥 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝐶 = 𝐷)
2625imbi1i 353 . . . . . . . . 9 ((𝑥 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝑥 = 𝑦) ↔ (𝐶 = 𝐷𝑥 = 𝑦))
27262ralbii 3158 . . . . . . . 8 (∀𝑥𝐴𝑦𝐴 (𝑥 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝑥 = 𝑦) ↔ ∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦))
28 nfcsb1v 3879 . . . . . . . . . . . 12 𝑥𝑦 / 𝑥𝐶
299, 28nfeq 2992 . . . . . . . . . . 11 𝑥𝑎 / 𝑥𝐶 = 𝑦 / 𝑥𝐶
30 nfv 1915 . . . . . . . . . . 11 𝑥 𝑎 = 𝑦
3129, 30nfim 1897 . . . . . . . . . 10 𝑥(𝑎 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝑎 = 𝑦)
32 nfv 1915 . . . . . . . . . 10 𝑦(𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏)
33 csbeq1 3858 . . . . . . . . . . . 12 (𝑥 = 𝑎𝑥 / 𝑥𝐶 = 𝑎 / 𝑥𝐶)
3433eqeq1d 2824 . . . . . . . . . . 11 (𝑥 = 𝑎 → (𝑥 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝑎 / 𝑥𝐶 = 𝑦 / 𝑥𝐶))
35 equequ1 2032 . . . . . . . . . . 11 (𝑥 = 𝑎 → (𝑥 = 𝑦𝑎 = 𝑦))
3634, 35imbi12d 348 . . . . . . . . . 10 (𝑥 = 𝑎 → ((𝑥 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝑥 = 𝑦) ↔ (𝑎 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝑎 = 𝑦)))
37 csbeq1 3858 . . . . . . . . . . . 12 (𝑦 = 𝑏𝑦 / 𝑥𝐶 = 𝑏 / 𝑥𝐶)
3837eqeq2d 2833 . . . . . . . . . . 11 (𝑦 = 𝑏 → (𝑎 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶))
39 equequ2 2033 . . . . . . . . . . 11 (𝑦 = 𝑏 → (𝑎 = 𝑦𝑎 = 𝑏))
4038, 39imbi12d 348 . . . . . . . . . 10 (𝑦 = 𝑏 → ((𝑎 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝑎 = 𝑦) ↔ (𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏)))
4131, 32, 36, 40rspc2 3606 . . . . . . . . 9 ((𝑎𝐴𝑏𝐴) → (∀𝑥𝐴𝑦𝐴 (𝑥 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝑥 = 𝑦) → (𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏)))
4241com12 32 . . . . . . . 8 (∀𝑥𝐴𝑦𝐴 (𝑥 / 𝑥𝐶 = 𝑦 / 𝑥𝐶𝑥 = 𝑦) → ((𝑎𝐴𝑏𝐴) → (𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏)))
4327, 42sylbir 238 . . . . . . 7 (∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦) → ((𝑎𝐴𝑏𝐴) → (𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏)))
44 id 22 . . . . . . . 8 ((𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏) → (𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏))
45 csbeq1 3858 . . . . . . . 8 (𝑎 = 𝑏𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶)
4644, 45impbid1 228 . . . . . . 7 ((𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏) → (𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏))
4743, 46syl6 35 . . . . . 6 (∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦) → ((𝑎𝐴𝑏𝐴) → (𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏)))
4847adantl 485 . . . . 5 ((𝜑 ∧ ∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦)) → ((𝑎𝐴𝑏𝐴) → (𝑎 / 𝑥𝐶 = 𝑏 / 𝑥𝐶𝑎 = 𝑏)))
4920, 48dom2d 8537 . . . 4 ((𝜑 ∧ ∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦)) → (𝐵 ∈ V → 𝐴𝐵))
507, 49mpd 15 . . 3 ((𝜑 ∧ ∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦)) → 𝐴𝐵)
513, 50mtand 815 . 2 (𝜑 → ¬ ∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦))
52 ancom 464 . . . . . . 7 ((¬ 𝑥 = 𝑦𝐶 = 𝐷) ↔ (𝐶 = 𝐷 ∧ ¬ 𝑥 = 𝑦))
53 df-ne 3012 . . . . . . . 8 (𝑥𝑦 ↔ ¬ 𝑥 = 𝑦)
5453anbi1i 626 . . . . . . 7 ((𝑥𝑦𝐶 = 𝐷) ↔ (¬ 𝑥 = 𝑦𝐶 = 𝐷))
55 pm4.61 408 . . . . . . 7 (¬ (𝐶 = 𝐷𝑥 = 𝑦) ↔ (𝐶 = 𝐷 ∧ ¬ 𝑥 = 𝑦))
5652, 54, 553bitr4i 306 . . . . . 6 ((𝑥𝑦𝐶 = 𝐷) ↔ ¬ (𝐶 = 𝐷𝑥 = 𝑦))
5756rexbii 3235 . . . . 5 (∃𝑦𝐴 (𝑥𝑦𝐶 = 𝐷) ↔ ∃𝑦𝐴 ¬ (𝐶 = 𝐷𝑥 = 𝑦))
58 rexnal 3226 . . . . 5 (∃𝑦𝐴 ¬ (𝐶 = 𝐷𝑥 = 𝑦) ↔ ¬ ∀𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦))
5957, 58bitri 278 . . . 4 (∃𝑦𝐴 (𝑥𝑦𝐶 = 𝐷) ↔ ¬ ∀𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦))
6059rexbii 3235 . . 3 (∃𝑥𝐴𝑦𝐴 (𝑥𝑦𝐶 = 𝐷) ↔ ∃𝑥𝐴 ¬ ∀𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦))
61 rexnal 3226 . . 3 (∃𝑥𝐴 ¬ ∀𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦) ↔ ¬ ∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦))
6260, 61bitri 278 . 2 (∃𝑥𝐴𝑦𝐴 (𝑥𝑦𝐶 = 𝐷) ↔ ¬ ∀𝑥𝐴𝑦𝐴 (𝐶 = 𝐷𝑥 = 𝑦))
6351, 62sylibr 237 1 (𝜑 → ∃𝑥𝐴𝑦𝐴 (𝑥𝑦𝐶 = 𝐷))
 Colors of variables: wff setvar class Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 209   ∧ wa 399   = wceq 1538   ∈ wcel 2114   ≠ wne 3011  ∀wral 3130  ∃wrex 3131  Vcvv 3469  ⦋csb 3855   class class class wbr 5042   ≼ cdom 8494   ≺ csdm 8495 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1911  ax-6 1970  ax-7 2015  ax-8 2116  ax-9 2124  ax-10 2145  ax-11 2161  ax-12 2178  ax-ext 2794  ax-rep 5166  ax-sep 5179  ax-nul 5186  ax-pow 5243  ax-pr 5307  ax-un 7446 This theorem depends on definitions:  df-bi 210  df-an 400  df-or 845  df-3an 1086  df-tru 1541  df-ex 1782  df-nf 1786  df-sb 2070  df-mo 2622  df-eu 2653  df-clab 2801  df-cleq 2815  df-clel 2894  df-nfc 2962  df-ne 3012  df-ral 3135  df-rex 3136  df-reu 3137  df-rab 3139  df-v 3471  df-sbc 3748  df-csb 3856  df-dif 3911  df-un 3913  df-in 3915  df-ss 3925  df-nul 4266  df-if 4440  df-pw 4513  df-sn 4540  df-pr 4542  df-op 4546  df-uni 4814  df-iun 4896  df-br 5043  df-opab 5105  df-mpt 5123  df-id 5437  df-xp 5538  df-rel 5539  df-cnv 5540  df-co 5541  df-dm 5542  df-rn 5543  df-res 5544  df-ima 5545  df-iota 6293  df-fun 6336  df-fn 6337  df-f 6338  df-f1 6339  df-fo 6340  df-f1o 6341  df-fv 6342  df-er 8276  df-en 8497  df-dom 8498  df-sdom 8499 This theorem is referenced by:  fphpdo  39688  pellex  39706
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