![]() |
Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > nbedgusgr | Structured version Visualization version GIF version |
Description: The number of neighbors of a vertex is the number of edges at the vertex in a simple graph. (Contributed by AV, 27-Dec-2020.) (Proof shortened by AV, 5-May-2021.) |
Ref | Expression |
---|---|
nbusgrf1o.v | ⊢ 𝑉 = (Vtx‘𝐺) |
nbusgrf1o.e | ⊢ 𝐸 = (Edg‘𝐺) |
Ref | Expression |
---|---|
nbedgusgr | ⊢ ((𝐺 ∈ USGraph ∧ 𝑈 ∈ 𝑉) → (♯‘(𝐺 NeighbVtx 𝑈)) = (♯‘{𝑒 ∈ 𝐸 ∣ 𝑈 ∈ 𝑒})) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ovex 6954 | . 2 ⊢ (𝐺 NeighbVtx 𝑈) ∈ V | |
2 | nbusgrf1o.v | . . 3 ⊢ 𝑉 = (Vtx‘𝐺) | |
3 | nbusgrf1o.e | . . 3 ⊢ 𝐸 = (Edg‘𝐺) | |
4 | 2, 3 | nbusgrf1o 26719 | . 2 ⊢ ((𝐺 ∈ USGraph ∧ 𝑈 ∈ 𝑉) → ∃𝑓 𝑓:(𝐺 NeighbVtx 𝑈)–1-1-onto→{𝑒 ∈ 𝐸 ∣ 𝑈 ∈ 𝑒}) |
5 | hasheqf1oi 13457 | . 2 ⊢ ((𝐺 NeighbVtx 𝑈) ∈ V → (∃𝑓 𝑓:(𝐺 NeighbVtx 𝑈)–1-1-onto→{𝑒 ∈ 𝐸 ∣ 𝑈 ∈ 𝑒} → (♯‘(𝐺 NeighbVtx 𝑈)) = (♯‘{𝑒 ∈ 𝐸 ∣ 𝑈 ∈ 𝑒}))) | |
6 | 1, 4, 5 | mpsyl 68 | 1 ⊢ ((𝐺 ∈ USGraph ∧ 𝑈 ∈ 𝑉) → (♯‘(𝐺 NeighbVtx 𝑈)) = (♯‘{𝑒 ∈ 𝐸 ∣ 𝑈 ∈ 𝑒})) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 386 = wceq 1601 ∃wex 1823 ∈ wcel 2107 {crab 3094 Vcvv 3398 –1-1-onto→wf1o 6134 ‘cfv 6135 (class class class)co 6922 ♯chash 13435 Vtxcvtx 26344 Edgcedg 26395 USGraphcusgr 26498 NeighbVtx cnbgr 26679 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1839 ax-4 1853 ax-5 1953 ax-6 2021 ax-7 2055 ax-8 2109 ax-9 2116 ax-10 2135 ax-11 2150 ax-12 2163 ax-13 2334 ax-ext 2754 ax-rep 5006 ax-sep 5017 ax-nul 5025 ax-pow 5077 ax-pr 5138 ax-un 7226 ax-cnex 10328 ax-resscn 10329 ax-1cn 10330 ax-icn 10331 ax-addcl 10332 ax-addrcl 10333 ax-mulcl 10334 ax-mulrcl 10335 ax-mulcom 10336 ax-addass 10337 ax-mulass 10338 ax-distr 10339 ax-i2m1 10340 ax-1ne0 10341 ax-1rid 10342 ax-rnegex 10343 ax-rrecex 10344 ax-cnre 10345 ax-pre-lttri 10346 ax-pre-lttrn 10347 ax-pre-ltadd 10348 ax-pre-mulgt0 10349 |
This theorem depends on definitions: df-bi 199 df-an 387 df-or 837 df-3or 1072 df-3an 1073 df-tru 1605 df-fal 1615 df-ex 1824 df-nf 1828 df-sb 2012 df-mo 2551 df-eu 2587 df-clab 2764 df-cleq 2770 df-clel 2774 df-nfc 2921 df-ne 2970 df-nel 3076 df-ral 3095 df-rex 3096 df-reu 3097 df-rmo 3098 df-rab 3099 df-v 3400 df-sbc 3653 df-csb 3752 df-dif 3795 df-un 3797 df-in 3799 df-ss 3806 df-pss 3808 df-nul 4142 df-if 4308 df-pw 4381 df-sn 4399 df-pr 4401 df-tp 4403 df-op 4405 df-uni 4672 df-int 4711 df-iun 4755 df-br 4887 df-opab 4949 df-mpt 4966 df-tr 4988 df-id 5261 df-eprel 5266 df-po 5274 df-so 5275 df-fr 5314 df-we 5316 df-xp 5361 df-rel 5362 df-cnv 5363 df-co 5364 df-dm 5365 df-rn 5366 df-res 5367 df-ima 5368 df-pred 5933 df-ord 5979 df-on 5980 df-lim 5981 df-suc 5982 df-iota 6099 df-fun 6137 df-fn 6138 df-f 6139 df-f1 6140 df-fo 6141 df-f1o 6142 df-fv 6143 df-riota 6883 df-ov 6925 df-oprab 6926 df-mpt2 6927 df-om 7344 df-1st 7445 df-2nd 7446 df-wrecs 7689 df-recs 7751 df-rdg 7789 df-1o 7843 df-2o 7844 df-oadd 7847 df-er 8026 df-en 8242 df-dom 8243 df-sdom 8244 df-fin 8245 df-card 9098 df-cda 9325 df-pnf 10413 df-mnf 10414 df-xr 10415 df-ltxr 10416 df-le 10417 df-sub 10608 df-neg 10609 df-nn 11375 df-2 11438 df-n0 11643 df-xnn0 11715 df-z 11729 df-uz 11993 df-fz 12644 df-hash 13436 df-edg 26396 df-upgr 26430 df-umgr 26431 df-uspgr 26499 df-usgr 26500 df-nbgr 26680 |
This theorem is referenced by: hashnbusgrvd 26876 rusgrpropedg 26932 |
Copyright terms: Public domain | W3C validator |