Users' Mathboxes Mathbox for Alexander van der Vekens < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >   Mathboxes  >  dfclnbgr6 Structured version   Visualization version   GIF version

Theorem dfclnbgr6 48478
Description: Alternate definition of the closed neighborhood of a vertex as union of the vertex with its semiopen neighborhood. (Contributed by AV, 17-May-2025.)
Hypotheses
Ref Expression
dfvopnbgr2.v 𝑉 = (Vtx‘𝐺)
dfvopnbgr2.e 𝐸 = (Edg‘𝐺)
dfvopnbgr2.u 𝑈 = {𝑛𝑉 ∣ (𝑛 ∈ (𝐺 NeighbVtx 𝑁) ∨ ∃𝑒𝐸 (𝑁 = 𝑛𝑒 = {𝑁}))}
Assertion
Ref Expression
dfclnbgr6 (𝑁𝑉 → (𝐺 ClNeighbVtx 𝑁) = ({𝑁} ∪ 𝑈))
Distinct variable groups:   𝑒,𝐸   𝑒,𝐺   𝑒,𝑁,𝑛   𝑒,𝑉,𝑛   𝑛,𝐸   𝑛,𝐺
Allowed substitution hints:   𝑈(𝑒,𝑛)

Proof of Theorem dfclnbgr6
Dummy variable 𝑣 is distinct from all other variables.
StepHypRef Expression
1 orc 878 . . . . . . 7 (𝑣 = 𝑁 → (𝑣 = 𝑁 ∨ ((𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒)) ↔ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))))
21a1d 25 . . . . . 6 (𝑣 = 𝑁 → (𝑁𝑉 → (𝑣 = 𝑁 ∨ ((𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒)) ↔ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣})))))))
3 simpl 486 . . . . . . . . . . . . . . 15 ((𝑣𝑁𝑁𝑉) → 𝑣𝑁)
43anim1i 624 . . . . . . . . . . . . . 14 (((𝑣𝑁𝑁𝑉) ∧ (𝑁𝑒𝑣𝑒)) → (𝑣𝑁 ∧ (𝑁𝑒𝑣𝑒)))
5 3anass 1106 . . . . . . . . . . . . . 14 ((𝑣𝑁𝑁𝑒𝑣𝑒) ↔ (𝑣𝑁 ∧ (𝑁𝑒𝑣𝑒)))
64, 5sylibr 236 . . . . . . . . . . . . 13 (((𝑣𝑁𝑁𝑉) ∧ (𝑁𝑒𝑣𝑒)) → (𝑣𝑁𝑁𝑒𝑣𝑒))
76orcd 884 . . . . . . . . . . . 12 (((𝑣𝑁𝑁𝑉) ∧ (𝑁𝑒𝑣𝑒)) → ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣})))
87ex 416 . . . . . . . . . . 11 ((𝑣𝑁𝑁𝑉) → ((𝑁𝑒𝑣𝑒) → ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))
9 3simpc 1163 . . . . . . . . . . . . 13 ((𝑣𝑁𝑁𝑒𝑣𝑒) → (𝑁𝑒𝑣𝑒))
109a1i 11 . . . . . . . . . . . 12 ((𝑣𝑁𝑁𝑉) → ((𝑣𝑁𝑁𝑒𝑣𝑒) → (𝑁𝑒𝑣𝑒)))
11 vsnid 4622 . . . . . . . . . . . . . . . . 17 𝑣 ∈ {𝑣}
12 eleq2 2851 . . . . . . . . . . . . . . . . 17 (𝑒 = {𝑣} → (𝑣𝑒𝑣 ∈ {𝑣}))
1311, 12mpbiri 260 . . . . . . . . . . . . . . . 16 (𝑒 = {𝑣} → 𝑣𝑒)
1413adantl 485 . . . . . . . . . . . . . . 15 ((𝑣 = 𝑁𝑒 = {𝑣}) → 𝑣𝑒)
15 eleq1 2850 . . . . . . . . . . . . . . . 16 (𝑣 = 𝑁 → (𝑣𝑒𝑁𝑒))
1615adantr 484 . . . . . . . . . . . . . . 15 ((𝑣 = 𝑁𝑒 = {𝑣}) → (𝑣𝑒𝑁𝑒))
1714, 16mpbid 234 . . . . . . . . . . . . . 14 ((𝑣 = 𝑁𝑒 = {𝑣}) → 𝑁𝑒)
1817, 14jca 519 . . . . . . . . . . . . 13 ((𝑣 = 𝑁𝑒 = {𝑣}) → (𝑁𝑒𝑣𝑒))
1918a1i 11 . . . . . . . . . . . 12 ((𝑣𝑁𝑁𝑉) → ((𝑣 = 𝑁𝑒 = {𝑣}) → (𝑁𝑒𝑣𝑒)))
2010, 19jaod 870 . . . . . . . . . . 11 ((𝑣𝑁𝑁𝑉) → (((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣})) → (𝑁𝑒𝑣𝑒)))
218, 20impbid 214 . . . . . . . . . 10 ((𝑣𝑁𝑁𝑉) → ((𝑁𝑒𝑣𝑒) ↔ ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))
2221rexbidv 3186 . . . . . . . . 9 ((𝑣𝑁𝑁𝑉) → (∃𝑒𝐸 (𝑁𝑒𝑣𝑒) ↔ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))
2322anbi2d 639 . . . . . . . 8 ((𝑣𝑁𝑁𝑉) → ((𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒)) ↔ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣})))))
2423olcd 885 . . . . . . 7 ((𝑣𝑁𝑁𝑉) → (𝑣 = 𝑁 ∨ ((𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒)) ↔ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))))
2524ex 416 . . . . . 6 (𝑣𝑁 → (𝑁𝑉 → (𝑣 = 𝑁 ∨ ((𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒)) ↔ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣})))))))
262, 25pm2.61ine 3040 . . . . 5 (𝑁𝑉 → (𝑣 = 𝑁 ∨ ((𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒)) ↔ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))))
27 orbidi 965 . . . . 5 ((𝑣 = 𝑁 ∨ ((𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒)) ↔ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))) ↔ ((𝑣 = 𝑁 ∨ (𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒))) ↔ (𝑣 = 𝑁 ∨ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))))
2826, 27sylib 220 . . . 4 (𝑁𝑉 → ((𝑣 = 𝑁 ∨ (𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒))) ↔ (𝑣 = 𝑁 ∨ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))))
29 elun 4106 . . . . 5 (𝑣 ∈ ({𝑁} ∪ {𝑛𝑉 ∣ ∃𝑒𝐸 (𝑁𝑒𝑛𝑒)}) ↔ (𝑣 ∈ {𝑁} ∨ 𝑣 ∈ {𝑛𝑉 ∣ ∃𝑒𝐸 (𝑁𝑒𝑛𝑒)}))
30 velsn 4598 . . . . . 6 (𝑣 ∈ {𝑁} ↔ 𝑣 = 𝑁)
31 eleq1 2850 . . . . . . . . 9 (𝑛 = 𝑣 → (𝑛𝑒𝑣𝑒))
3231anbi2d 639 . . . . . . . 8 (𝑛 = 𝑣 → ((𝑁𝑒𝑛𝑒) ↔ (𝑁𝑒𝑣𝑒)))
3332rexbidv 3186 . . . . . . 7 (𝑛 = 𝑣 → (∃𝑒𝐸 (𝑁𝑒𝑛𝑒) ↔ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒)))
3433elrab 3650 . . . . . 6 (𝑣 ∈ {𝑛𝑉 ∣ ∃𝑒𝐸 (𝑁𝑒𝑛𝑒)} ↔ (𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒)))
3530, 34orbi12i 925 . . . . 5 ((𝑣 ∈ {𝑁} ∨ 𝑣 ∈ {𝑛𝑉 ∣ ∃𝑒𝐸 (𝑁𝑒𝑛𝑒)}) ↔ (𝑣 = 𝑁 ∨ (𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒))))
3629, 35bitri 277 . . . 4 (𝑣 ∈ ({𝑁} ∪ {𝑛𝑉 ∣ ∃𝑒𝐸 (𝑁𝑒𝑛𝑒)}) ↔ (𝑣 = 𝑁 ∨ (𝑣𝑉 ∧ ∃𝑒𝐸 (𝑁𝑒𝑣𝑒))))
37 elun 4106 . . . . 5 (𝑣 ∈ ({𝑁} ∪ {𝑛𝑉 ∣ ∃𝑒𝐸 ((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛}))}) ↔ (𝑣 ∈ {𝑁} ∨ 𝑣 ∈ {𝑛𝑉 ∣ ∃𝑒𝐸 ((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛}))}))
38 neeq1 3019 . . . . . . . . . 10 (𝑛 = 𝑣 → (𝑛𝑁𝑣𝑁))
3938, 313anbi13d 1459 . . . . . . . . 9 (𝑛 = 𝑣 → ((𝑛𝑁𝑁𝑒𝑛𝑒) ↔ (𝑣𝑁𝑁𝑒𝑣𝑒)))
40 eqeq1 2766 . . . . . . . . . 10 (𝑛 = 𝑣 → (𝑛 = 𝑁𝑣 = 𝑁))
41 sneq 4592 . . . . . . . . . . 11 (𝑛 = 𝑣 → {𝑛} = {𝑣})
4241eqeq2d 2773 . . . . . . . . . 10 (𝑛 = 𝑣 → (𝑒 = {𝑛} ↔ 𝑒 = {𝑣}))
4340, 42anbi12d 641 . . . . . . . . 9 (𝑛 = 𝑣 → ((𝑛 = 𝑁𝑒 = {𝑛}) ↔ (𝑣 = 𝑁𝑒 = {𝑣})))
4439, 43orbi12d 929 . . . . . . . 8 (𝑛 = 𝑣 → (((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛})) ↔ ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))
4544rexbidv 3186 . . . . . . 7 (𝑛 = 𝑣 → (∃𝑒𝐸 ((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛})) ↔ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))
4645elrab 3650 . . . . . 6 (𝑣 ∈ {𝑛𝑉 ∣ ∃𝑒𝐸 ((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛}))} ↔ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣}))))
4730, 46orbi12i 925 . . . . 5 ((𝑣 ∈ {𝑁} ∨ 𝑣 ∈ {𝑛𝑉 ∣ ∃𝑒𝐸 ((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛}))}) ↔ (𝑣 = 𝑁 ∨ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣})))))
4837, 47bitri 277 . . . 4 (𝑣 ∈ ({𝑁} ∪ {𝑛𝑉 ∣ ∃𝑒𝐸 ((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛}))}) ↔ (𝑣 = 𝑁 ∨ (𝑣𝑉 ∧ ∃𝑒𝐸 ((𝑣𝑁𝑁𝑒𝑣𝑒) ∨ (𝑣 = 𝑁𝑒 = {𝑣})))))
4928, 36, 483bitr4g 316 . . 3 (𝑁𝑉 → (𝑣 ∈ ({𝑁} ∪ {𝑛𝑉 ∣ ∃𝑒𝐸 (𝑁𝑒𝑛𝑒)}) ↔ 𝑣 ∈ ({𝑁} ∪ {𝑛𝑉 ∣ ∃𝑒𝐸 ((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛}))})))
5049eqrdv 2760 . 2 (𝑁𝑉 → ({𝑁} ∪ {𝑛𝑉 ∣ ∃𝑒𝐸 (𝑁𝑒𝑛𝑒)}) = ({𝑁} ∪ {𝑛𝑉 ∣ ∃𝑒𝐸 ((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛}))}))
51 dfvopnbgr2.v . . 3 𝑉 = (Vtx‘𝐺)
52 dfvopnbgr2.e . . 3 𝐸 = (Edg‘𝐺)
5351, 52dfclnbgr2 48445 . 2 (𝑁𝑉 → (𝐺 ClNeighbVtx 𝑁) = ({𝑁} ∪ {𝑛𝑉 ∣ ∃𝑒𝐸 (𝑁𝑒𝑛𝑒)}))
54 dfvopnbgr2.u . . . 4 𝑈 = {𝑛𝑉 ∣ (𝑛 ∈ (𝐺 NeighbVtx 𝑁) ∨ ∃𝑒𝐸 (𝑁 = 𝑛𝑒 = {𝑁}))}
5551, 52, 54dfvopnbgr2 48475 . . 3 (𝑁𝑉𝑈 = {𝑛𝑉 ∣ ∃𝑒𝐸 ((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛}))})
5655uneq2d 4121 . 2 (𝑁𝑉 → ({𝑁} ∪ 𝑈) = ({𝑁} ∪ {𝑛𝑉 ∣ ∃𝑒𝐸 ((𝑛𝑁𝑁𝑒𝑛𝑒) ∨ (𝑛 = 𝑁𝑒 = {𝑛}))}))
5750, 53, 563eqtr4d 2807 1 (𝑁𝑉 → (𝐺 ClNeighbVtx 𝑁) = ({𝑁} ∪ 𝑈))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 208  wa 399  wo 858  w3a 1098   = wceq 1560  wcel 2142  wne 2957  wrex 3086  {crab 3414  cun 3902  {csn 4582  cfv 6521  (class class class)co 7396  Vtxcvtx 29197  Edgcedg 29248   NeighbVtx cnbgr 29533   ClNeighbVtx cclnbgr 48440
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1815  ax-4 1829  ax-5 1930  ax-6 1987  ax-7 2028  ax-8 2144  ax-9 2152  ax-10 2175  ax-11 2191  ax-12 2212  ax-ext 2734  ax-sep 5246  ax-nul 5256  ax-pr 5390  ax-un 7718
This theorem depends on definitions:  df-bi 209  df-an 400  df-or 859  df-3an 1100  df-tru 1563  df-fal 1573  df-ex 1800  df-nf 1804  df-sb 2091  df-mo 2566  df-eu 2596  df-clab 2741  df-cleq 2754  df-clel 2837  df-nfc 2911  df-ne 2958  df-ral 3077  df-rex 3087  df-rab 3415  df-v 3456  df-sbc 3745  df-csb 3853  df-dif 3907  df-un 3909  df-in 3911  df-ss 3921  df-nul 4286  df-if 4481  df-pw 4557  df-sn 4583  df-pr 4585  df-op 4589  df-uni 4866  df-iun 4951  df-br 5101  df-opab 5163  df-mpt 5182  df-id 5542  df-xp 5653  df-rel 5654  df-cnv 5655  df-co 5656  df-dm 5657  df-rn 5658  df-res 5659  df-ima 5660  df-iota 6477  df-fun 6523  df-fv 6529  df-ov 7399  df-oprab 7400  df-mpo 7401  df-1st 7970  df-2nd 7971  df-nbgr 29534  df-clnbgr 48441
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator