Users' Mathboxes Mathbox for Alexander van der Vekens < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >   Mathboxes  >  frgrncvvdeqlemA Structured version   Visualization version   GIF version

Theorem frgrncvvdeqlemA 41478
Description: Lemma A for frgrncvvdeq 41482. This corresponds to statement 1 in [Huneke] p. 1: "This common neighbor cannot be x, as x and y are not adjacent.". This is only an observation, which is not required to proof the friendship theorem. (Contributed by Alexander van der Vekens, 23-Dec-2017.) (Revised by AV, 10-May-2021.)
Hypotheses
Ref Expression
frgrncvvdeq.v1 𝑉 = (Vtx‘𝐺)
frgrncvvdeq.e 𝐸 = (Edg‘𝐺)
frgrncvvdeq.nx 𝐷 = (𝐺 NeighbVtx 𝑋)
frgrncvvdeq.ny 𝑁 = (𝐺 NeighbVtx 𝑌)
frgrncvvdeq.x (𝜑𝑋𝑉)
frgrncvvdeq.y (𝜑𝑌𝑉)
frgrncvvdeq.ne (𝜑𝑋𝑌)
frgrncvvdeq.xy (𝜑𝑌𝐷)
frgrncvvdeq.f (𝜑𝐺 ∈ FriendGraph )
frgrncvvdeq.a 𝐴 = (𝑥𝐷 ↦ (𝑦𝑁 {𝑥, 𝑦} ∈ 𝐸))
Assertion
Ref Expression
frgrncvvdeqlemA (𝜑 → ∀𝑥𝐷 (𝐴𝑥) ≠ 𝑋)
Distinct variable groups:   𝑦,𝐷   𝑦,𝐺   𝑦,𝑉   𝑦,𝑌   𝜑,𝑦,𝑥   𝑦,𝐸   𝑦,𝑁   𝑥,𝐷   𝑥,𝑁   𝜑,𝑥
Allowed substitution hints:   𝐴(𝑥,𝑦)   𝐸(𝑥)   𝐺(𝑥)   𝑉(𝑥)   𝑋(𝑥,𝑦)   𝑌(𝑥)

Proof of Theorem frgrncvvdeqlemA
StepHypRef Expression
1 frgrncvvdeq.v1 . . . 4 𝑉 = (Vtx‘𝐺)
2 frgrncvvdeq.e . . . 4 𝐸 = (Edg‘𝐺)
3 frgrncvvdeq.nx . . . 4 𝐷 = (𝐺 NeighbVtx 𝑋)
4 frgrncvvdeq.ny . . . 4 𝑁 = (𝐺 NeighbVtx 𝑌)
5 frgrncvvdeq.x . . . 4 (𝜑𝑋𝑉)
6 frgrncvvdeq.y . . . 4 (𝜑𝑌𝑉)
7 frgrncvvdeq.ne . . . 4 (𝜑𝑋𝑌)
8 frgrncvvdeq.xy . . . 4 (𝜑𝑌𝐷)
9 frgrncvvdeq.f . . . 4 (𝜑𝐺 ∈ FriendGraph )
10 frgrncvvdeq.a . . . 4 𝐴 = (𝑥𝐷 ↦ (𝑦𝑁 {𝑥, 𝑦} ∈ 𝐸))
111, 2, 3, 4, 5, 6, 7, 8, 9, 10frgrncvvdeqlem6 41476 . . 3 ((𝜑𝑥𝐷) → {(𝐴𝑥)} = ((𝐺 NeighbVtx 𝑥) ∩ 𝑁))
12 fvex 6098 . . . . 5 (𝐴𝑥) ∈ V
1312snid 4154 . . . 4 (𝐴𝑥) ∈ {(𝐴𝑥)}
14 eleq2 2676 . . . . . 6 ({(𝐴𝑥)} = ((𝐺 NeighbVtx 𝑥) ∩ 𝑁) → ((𝐴𝑥) ∈ {(𝐴𝑥)} ↔ (𝐴𝑥) ∈ ((𝐺 NeighbVtx 𝑥) ∩ 𝑁)))
1514biimpa 499 . . . . 5 (({(𝐴𝑥)} = ((𝐺 NeighbVtx 𝑥) ∩ 𝑁) ∧ (𝐴𝑥) ∈ {(𝐴𝑥)}) → (𝐴𝑥) ∈ ((𝐺 NeighbVtx 𝑥) ∩ 𝑁))
16 elin 3757 . . . . . 6 ((𝐴𝑥) ∈ ((𝐺 NeighbVtx 𝑥) ∩ 𝑁) ↔ ((𝐴𝑥) ∈ (𝐺 NeighbVtx 𝑥) ∧ (𝐴𝑥) ∈ 𝑁))
171, 2, 3, 4, 5, 6, 7, 8, 9, 10frgrncvvdeqlem2 41472 . . . . . . . . 9 (𝜑𝑋𝑁)
18 df-nel 2782 . . . . . . . . . 10 (𝑋𝑁 ↔ ¬ 𝑋𝑁)
19 nelelne 2879 . . . . . . . . . 10 𝑋𝑁 → ((𝐴𝑥) ∈ 𝑁 → (𝐴𝑥) ≠ 𝑋))
2018, 19sylbi 205 . . . . . . . . 9 (𝑋𝑁 → ((𝐴𝑥) ∈ 𝑁 → (𝐴𝑥) ≠ 𝑋))
2117, 20syl 17 . . . . . . . 8 (𝜑 → ((𝐴𝑥) ∈ 𝑁 → (𝐴𝑥) ≠ 𝑋))
2221adantr 479 . . . . . . 7 ((𝜑𝑥𝐷) → ((𝐴𝑥) ∈ 𝑁 → (𝐴𝑥) ≠ 𝑋))
2322com12 32 . . . . . 6 ((𝐴𝑥) ∈ 𝑁 → ((𝜑𝑥𝐷) → (𝐴𝑥) ≠ 𝑋))
2416, 23simplbiim 656 . . . . 5 ((𝐴𝑥) ∈ ((𝐺 NeighbVtx 𝑥) ∩ 𝑁) → ((𝜑𝑥𝐷) → (𝐴𝑥) ≠ 𝑋))
2515, 24syl 17 . . . 4 (({(𝐴𝑥)} = ((𝐺 NeighbVtx 𝑥) ∩ 𝑁) ∧ (𝐴𝑥) ∈ {(𝐴𝑥)}) → ((𝜑𝑥𝐷) → (𝐴𝑥) ≠ 𝑋))
2613, 25mpan2 702 . . 3 ({(𝐴𝑥)} = ((𝐺 NeighbVtx 𝑥) ∩ 𝑁) → ((𝜑𝑥𝐷) → (𝐴𝑥) ≠ 𝑋))
2711, 26mpcom 37 . 2 ((𝜑𝑥𝐷) → (𝐴𝑥) ≠ 𝑋)
2827ralrimiva 2948 1 (𝜑 → ∀𝑥𝐷 (𝐴𝑥) ≠ 𝑋)
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wi 4  wa 382   = wceq 1474  wcel 1976  wne 2779  wnel 2780  wral 2895  cin 3538  {csn 4124  {cpr 4126  cmpt 4637  cfv 5790  crio 6488  (class class class)co 6527  Vtxcvtx 40231  Edgcedga 40353   NeighbVtx cnbgr 40552   FriendGraph cfrgr 41430
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1712  ax-4 1727  ax-5 1826  ax-6 1874  ax-7 1921  ax-8 1978  ax-9 1985  ax-10 2005  ax-11 2020  ax-12 2032  ax-13 2232  ax-ext 2589  ax-rep 4693  ax-sep 4703  ax-nul 4712  ax-pow 4764  ax-pr 4828  ax-un 6824  ax-cnex 9848  ax-resscn 9849  ax-1cn 9850  ax-icn 9851  ax-addcl 9852  ax-addrcl 9853  ax-mulcl 9854  ax-mulrcl 9855  ax-mulcom 9856  ax-addass 9857  ax-mulass 9858  ax-distr 9859  ax-i2m1 9860  ax-1ne0 9861  ax-1rid 9862  ax-rnegex 9863  ax-rrecex 9864  ax-cnre 9865  ax-pre-lttri 9866  ax-pre-lttrn 9867  ax-pre-ltadd 9868  ax-pre-mulgt0 9869
This theorem depends on definitions:  df-bi 195  df-or 383  df-an 384  df-3or 1031  df-3an 1032  df-tru 1477  df-fal 1480  df-ex 1695  df-nf 1700  df-sb 1867  df-eu 2461  df-mo 2462  df-clab 2596  df-cleq 2602  df-clel 2605  df-nfc 2739  df-ne 2781  df-nel 2782  df-ral 2900  df-rex 2901  df-reu 2902  df-rmo 2903  df-rab 2904  df-v 3174  df-sbc 3402  df-csb 3499  df-dif 3542  df-un 3544  df-in 3546  df-ss 3553  df-pss 3555  df-nul 3874  df-if 4036  df-pw 4109  df-sn 4125  df-pr 4127  df-tp 4129  df-op 4131  df-uni 4367  df-int 4405  df-iun 4451  df-br 4578  df-opab 4638  df-mpt 4639  df-tr 4675  df-eprel 4939  df-id 4943  df-po 4949  df-so 4950  df-fr 4987  df-we 4989  df-xp 5034  df-rel 5035  df-cnv 5036  df-co 5037  df-dm 5038  df-rn 5039  df-res 5040  df-ima 5041  df-pred 5583  df-ord 5629  df-on 5630  df-lim 5631  df-suc 5632  df-iota 5754  df-fun 5792  df-fn 5793  df-f 5794  df-f1 5795  df-fo 5796  df-f1o 5797  df-fv 5798  df-riota 6489  df-ov 6530  df-oprab 6531  df-mpt2 6532  df-om 6935  df-1st 7036  df-2nd 7037  df-wrecs 7271  df-recs 7332  df-rdg 7370  df-1o 7424  df-2o 7425  df-oadd 7428  df-er 7606  df-en 7819  df-dom 7820  df-sdom 7821  df-fin 7822  df-card 8625  df-cda 8850  df-pnf 9932  df-mnf 9933  df-xr 9934  df-ltxr 9935  df-le 9936  df-sub 10119  df-neg 10120  df-nn 10868  df-2 10926  df-n0 11140  df-z 11211  df-uz 11520  df-fz 12153  df-hash 12935  df-upgr 40310  df-umgr 40311  df-edga 40354  df-usgr 40383  df-nbgr 40556  df-frgr 41431
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator