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Mirrors > Home > MPE Home > Th. List > nbusgrf1o1 | Structured version Visualization version GIF version |
Description: The set of neighbors of a vertex is isomorphic to the set of edges containing the vertex in a simple graph. (Contributed by Alexander van der Vekens, 19-Dec-2017.) (Revised by AV, 28-Oct-2020.) |
Ref | Expression |
---|---|
nbusgrf1o1.v | ⊢ 𝑉 = (Vtx‘𝐺) |
nbusgrf1o1.e | ⊢ 𝐸 = (Edg‘𝐺) |
nbusgrf1o1.n | ⊢ 𝑁 = (𝐺 NeighbVtx 𝑈) |
nbusgrf1o1.i | ⊢ 𝐼 = {𝑒 ∈ 𝐸 ∣ 𝑈 ∈ 𝑒} |
Ref | Expression |
---|---|
nbusgrf1o1 | ⊢ ((𝐺 ∈ USGraph ∧ 𝑈 ∈ 𝑉) → ∃𝑓 𝑓:𝑁–1-1-onto→𝐼) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nbusgrf1o1.n | . . . 4 ⊢ 𝑁 = (𝐺 NeighbVtx 𝑈) | |
2 | 1 | ovexi 7305 | . . 3 ⊢ 𝑁 ∈ V |
3 | mptexg 7094 | . . 3 ⊢ (𝑁 ∈ V → (𝑛 ∈ 𝑁 ↦ {𝑈, 𝑛}) ∈ V) | |
4 | 2, 3 | mp1i 13 | . 2 ⊢ ((𝐺 ∈ USGraph ∧ 𝑈 ∈ 𝑉) → (𝑛 ∈ 𝑁 ↦ {𝑈, 𝑛}) ∈ V) |
5 | nbusgrf1o1.v | . . 3 ⊢ 𝑉 = (Vtx‘𝐺) | |
6 | nbusgrf1o1.e | . . 3 ⊢ 𝐸 = (Edg‘𝐺) | |
7 | nbusgrf1o1.i | . . 3 ⊢ 𝐼 = {𝑒 ∈ 𝐸 ∣ 𝑈 ∈ 𝑒} | |
8 | eqid 2740 | . . 3 ⊢ (𝑛 ∈ 𝑁 ↦ {𝑈, 𝑛}) = (𝑛 ∈ 𝑁 ↦ {𝑈, 𝑛}) | |
9 | 5, 6, 1, 7, 8 | nbusgrf1o0 27734 | . 2 ⊢ ((𝐺 ∈ USGraph ∧ 𝑈 ∈ 𝑉) → (𝑛 ∈ 𝑁 ↦ {𝑈, 𝑛}):𝑁–1-1-onto→𝐼) |
10 | f1oeq1 6702 | . 2 ⊢ (𝑓 = (𝑛 ∈ 𝑁 ↦ {𝑈, 𝑛}) → (𝑓:𝑁–1-1-onto→𝐼 ↔ (𝑛 ∈ 𝑁 ↦ {𝑈, 𝑛}):𝑁–1-1-onto→𝐼)) | |
11 | 4, 9, 10 | spcedv 3536 | 1 ⊢ ((𝐺 ∈ USGraph ∧ 𝑈 ∈ 𝑉) → ∃𝑓 𝑓:𝑁–1-1-onto→𝐼) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 396 = wceq 1542 ∃wex 1786 ∈ wcel 2110 {crab 3070 Vcvv 3431 {cpr 4569 ↦ cmpt 5162 –1-1-onto→wf1o 6431 ‘cfv 6432 (class class class)co 7271 Vtxcvtx 27364 Edgcedg 27415 USGraphcusgr 27517 NeighbVtx cnbgr 27697 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1802 ax-4 1816 ax-5 1917 ax-6 1975 ax-7 2015 ax-8 2112 ax-9 2120 ax-10 2141 ax-11 2158 ax-12 2175 ax-ext 2711 ax-rep 5214 ax-sep 5227 ax-nul 5234 ax-pow 5292 ax-pr 5356 ax-un 7582 ax-cnex 10928 ax-resscn 10929 ax-1cn 10930 ax-icn 10931 ax-addcl 10932 ax-addrcl 10933 ax-mulcl 10934 ax-mulrcl 10935 ax-mulcom 10936 ax-addass 10937 ax-mulass 10938 ax-distr 10939 ax-i2m1 10940 ax-1ne0 10941 ax-1rid 10942 ax-rnegex 10943 ax-rrecex 10944 ax-cnre 10945 ax-pre-lttri 10946 ax-pre-lttrn 10947 ax-pre-ltadd 10948 ax-pre-mulgt0 10949 |
This theorem depends on definitions: df-bi 206 df-an 397 df-or 845 df-3or 1087 df-3an 1088 df-tru 1545 df-fal 1555 df-ex 1787 df-nf 1791 df-sb 2072 df-mo 2542 df-eu 2571 df-clab 2718 df-cleq 2732 df-clel 2818 df-nfc 2891 df-ne 2946 df-nel 3052 df-ral 3071 df-rex 3072 df-reu 3073 df-rmo 3074 df-rab 3075 df-v 3433 df-sbc 3721 df-csb 3838 df-dif 3895 df-un 3897 df-in 3899 df-ss 3909 df-pss 3911 df-nul 4263 df-if 4466 df-pw 4541 df-sn 4568 df-pr 4570 df-op 4574 df-uni 4846 df-int 4886 df-iun 4932 df-br 5080 df-opab 5142 df-mpt 5163 df-tr 5197 df-id 5490 df-eprel 5496 df-po 5504 df-so 5505 df-fr 5545 df-we 5547 df-xp 5596 df-rel 5597 df-cnv 5598 df-co 5599 df-dm 5600 df-rn 5601 df-res 5602 df-ima 5603 df-pred 6201 df-ord 6268 df-on 6269 df-lim 6270 df-suc 6271 df-iota 6390 df-fun 6434 df-fn 6435 df-f 6436 df-f1 6437 df-fo 6438 df-f1o 6439 df-fv 6440 df-riota 7228 df-ov 7274 df-oprab 7275 df-mpo 7276 df-om 7707 df-1st 7824 df-2nd 7825 df-frecs 8088 df-wrecs 8119 df-recs 8193 df-rdg 8232 df-1o 8288 df-2o 8289 df-oadd 8292 df-er 8481 df-en 8717 df-dom 8718 df-sdom 8719 df-fin 8720 df-dju 9660 df-card 9698 df-pnf 11012 df-mnf 11013 df-xr 11014 df-ltxr 11015 df-le 11016 df-sub 11207 df-neg 11208 df-nn 11974 df-2 12036 df-n0 12234 df-xnn0 12306 df-z 12320 df-uz 12582 df-fz 13239 df-hash 14043 df-edg 27416 df-upgr 27450 df-umgr 27451 df-uspgr 27518 df-usgr 27519 df-nbgr 27698 |
This theorem is referenced by: nbusgrf1o 27736 |
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