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Mirrors > Home > MPE Home > Th. List > nbfusgrlevtxm2 | Structured version Visualization version GIF version |
Description: If there is a vertex which is not a neighbor of another vertex, the number of neighbors of the other vertex is at most the number of vertices of the graph minus 2 in a finite simple graph. (Contributed by AV, 16-Dec-2020.) |
Ref | Expression |
---|---|
hashnbusgrnn0.v | ⊢ 𝑉 = (Vtx‘𝐺) |
Ref | Expression |
---|---|
nbfusgrlevtxm2 | ⊢ (((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) ∧ (𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈))) → (#‘(𝐺 NeighbVtx 𝑈)) ≤ ((#‘𝑉) − 2)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | hashnbusgrnn0.v | . . . . 5 ⊢ 𝑉 = (Vtx‘𝐺) | |
2 | fvex 6201 | . . . . 5 ⊢ (Vtx‘𝐺) ∈ V | |
3 | 1, 2 | eqeltri 2697 | . . . 4 ⊢ 𝑉 ∈ V |
4 | difexg 4808 | . . . 4 ⊢ (𝑉 ∈ V → (𝑉 ∖ {𝑀, 𝑈}) ∈ V) | |
5 | 3, 4 | mp1i 13 | . . 3 ⊢ (((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) ∧ (𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈))) → (𝑉 ∖ {𝑀, 𝑈}) ∈ V) |
6 | simpl 473 | . . . 4 ⊢ ((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) → 𝐺 ∈ FinUSGraph ) | |
7 | simp3 1063 | . . . 4 ⊢ ((𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈)) → 𝑀 ∉ (𝐺 NeighbVtx 𝑈)) | |
8 | 1 | nbgrssvwo2 26261 | . . . 4 ⊢ ((𝐺 ∈ FinUSGraph ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈)) → (𝐺 NeighbVtx 𝑈) ⊆ (𝑉 ∖ {𝑀, 𝑈})) |
9 | 6, 7, 8 | syl2an 494 | . . 3 ⊢ (((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) ∧ (𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈))) → (𝐺 NeighbVtx 𝑈) ⊆ (𝑉 ∖ {𝑀, 𝑈})) |
10 | hashss 13197 | . . 3 ⊢ (((𝑉 ∖ {𝑀, 𝑈}) ∈ V ∧ (𝐺 NeighbVtx 𝑈) ⊆ (𝑉 ∖ {𝑀, 𝑈})) → (#‘(𝐺 NeighbVtx 𝑈)) ≤ (#‘(𝑉 ∖ {𝑀, 𝑈}))) | |
11 | 5, 9, 10 | syl2anc 693 | . 2 ⊢ (((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) ∧ (𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈))) → (#‘(𝐺 NeighbVtx 𝑈)) ≤ (#‘(𝑉 ∖ {𝑀, 𝑈}))) |
12 | 1 | isfusgr 26210 | . . . . . 6 ⊢ (𝐺 ∈ FinUSGraph ↔ (𝐺 ∈ USGraph ∧ 𝑉 ∈ Fin)) |
13 | 12 | simprbi 480 | . . . . 5 ⊢ (𝐺 ∈ FinUSGraph → 𝑉 ∈ Fin) |
14 | 13 | adantr 481 | . . . 4 ⊢ ((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) → 𝑉 ∈ Fin) |
15 | 14 | adantr 481 | . . 3 ⊢ (((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) ∧ (𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈))) → 𝑉 ∈ Fin) |
16 | simpr1 1067 | . . 3 ⊢ (((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) ∧ (𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈))) → 𝑀 ∈ 𝑉) | |
17 | simplr 792 | . . 3 ⊢ (((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) ∧ (𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈))) → 𝑈 ∈ 𝑉) | |
18 | simpr2 1068 | . . 3 ⊢ (((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) ∧ (𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈))) → 𝑀 ≠ 𝑈) | |
19 | hashdifpr 13203 | . . 3 ⊢ ((𝑉 ∈ Fin ∧ (𝑀 ∈ 𝑉 ∧ 𝑈 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈)) → (#‘(𝑉 ∖ {𝑀, 𝑈})) = ((#‘𝑉) − 2)) | |
20 | 15, 16, 17, 18, 19 | syl13anc 1328 | . 2 ⊢ (((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) ∧ (𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈))) → (#‘(𝑉 ∖ {𝑀, 𝑈})) = ((#‘𝑉) − 2)) |
21 | 11, 20 | breqtrd 4679 | 1 ⊢ (((𝐺 ∈ FinUSGraph ∧ 𝑈 ∈ 𝑉) ∧ (𝑀 ∈ 𝑉 ∧ 𝑀 ≠ 𝑈 ∧ 𝑀 ∉ (𝐺 NeighbVtx 𝑈))) → (#‘(𝐺 NeighbVtx 𝑈)) ≤ ((#‘𝑉) − 2)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 384 ∧ w3a 1037 = wceq 1483 ∈ wcel 1990 ≠ wne 2794 ∉ wnel 2897 Vcvv 3200 ∖ cdif 3571 ⊆ wss 3574 {cpr 4179 class class class wbr 4653 ‘cfv 5888 (class class class)co 6650 Fincfn 7955 ≤ cle 10075 − cmin 10266 2c2 11070 #chash 13117 Vtxcvtx 25874 USGraph cusgr 26044 FinUSGraph cfusgr 26208 NeighbVtx cnbgr 26224 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1722 ax-4 1737 ax-5 1839 ax-6 1888 ax-7 1935 ax-8 1992 ax-9 1999 ax-10 2019 ax-11 2034 ax-12 2047 ax-13 2246 ax-ext 2602 ax-rep 4771 ax-sep 4781 ax-nul 4789 ax-pow 4843 ax-pr 4906 ax-un 6949 ax-cnex 9992 ax-resscn 9993 ax-1cn 9994 ax-icn 9995 ax-addcl 9996 ax-addrcl 9997 ax-mulcl 9998 ax-mulrcl 9999 ax-mulcom 10000 ax-addass 10001 ax-mulass 10002 ax-distr 10003 ax-i2m1 10004 ax-1ne0 10005 ax-1rid 10006 ax-rnegex 10007 ax-rrecex 10008 ax-cnre 10009 ax-pre-lttri 10010 ax-pre-lttrn 10011 ax-pre-ltadd 10012 ax-pre-mulgt0 10013 |
This theorem depends on definitions: df-bi 197 df-or 385 df-an 386 df-3or 1038 df-3an 1039 df-tru 1486 df-fal 1489 df-ex 1705 df-nf 1710 df-sb 1881 df-eu 2474 df-mo 2475 df-clab 2609 df-cleq 2615 df-clel 2618 df-nfc 2753 df-ne 2795 df-nel 2898 df-ral 2917 df-rex 2918 df-reu 2919 df-rmo 2920 df-rab 2921 df-v 3202 df-sbc 3436 df-csb 3534 df-dif 3577 df-un 3579 df-in 3581 df-ss 3588 df-pss 3590 df-nul 3916 df-if 4087 df-pw 4160 df-sn 4178 df-pr 4180 df-tp 4182 df-op 4184 df-uni 4437 df-int 4476 df-iun 4522 df-br 4654 df-opab 4713 df-mpt 4730 df-tr 4753 df-id 5024 df-eprel 5029 df-po 5035 df-so 5036 df-fr 5073 df-we 5075 df-xp 5120 df-rel 5121 df-cnv 5122 df-co 5123 df-dm 5124 df-rn 5125 df-res 5126 df-ima 5127 df-pred 5680 df-ord 5726 df-on 5727 df-lim 5728 df-suc 5729 df-iota 5851 df-fun 5890 df-fn 5891 df-f 5892 df-f1 5893 df-fo 5894 df-f1o 5895 df-fv 5896 df-riota 6611 df-ov 6653 df-oprab 6654 df-mpt2 6655 df-om 7066 df-1st 7168 df-2nd 7169 df-wrecs 7407 df-recs 7468 df-rdg 7506 df-1o 7560 df-oadd 7564 df-er 7742 df-en 7956 df-dom 7957 df-sdom 7958 df-fin 7959 df-card 8765 df-cda 8990 df-pnf 10076 df-mnf 10077 df-xr 10078 df-ltxr 10079 df-le 10080 df-sub 10268 df-neg 10269 df-nn 11021 df-2 11079 df-n0 11293 df-xnn0 11364 df-z 11378 df-uz 11688 df-fz 12327 df-hash 13118 df-fusgr 26209 df-nbgr 26228 |
This theorem is referenced by: nbusgrvtxm1 26281 |
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