Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > MPE Home > Th. List > usgrres | Structured version Visualization version GIF version |
Description: A subgraph obtained by removing one vertex and all edges incident with this vertex from a simple graph (see uhgrspan1 27613) is a simple graph. (Contributed by Alexander van der Vekens, 2-Jan-2018.) (Revised by AV, 19-Dec-2021.) |
Ref | Expression |
---|---|
upgrres.v | ⊢ 𝑉 = (Vtx‘𝐺) |
upgrres.e | ⊢ 𝐸 = (iEdg‘𝐺) |
upgrres.f | ⊢ 𝐹 = {𝑖 ∈ dom 𝐸 ∣ 𝑁 ∉ (𝐸‘𝑖)} |
upgrres.s | ⊢ 𝑆 = 〈(𝑉 ∖ {𝑁}), (𝐸 ↾ 𝐹)〉 |
Ref | Expression |
---|---|
usgrres | ⊢ ((𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉) → 𝑆 ∈ USGraph) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | upgrres.v | . . . . . 6 ⊢ 𝑉 = (Vtx‘𝐺) | |
2 | upgrres.e | . . . . . 6 ⊢ 𝐸 = (iEdg‘𝐺) | |
3 | 1, 2 | usgrf 27468 | . . . . 5 ⊢ (𝐺 ∈ USGraph → 𝐸:dom 𝐸–1-1→{𝑥 ∈ (𝒫 𝑉 ∖ {∅}) ∣ (♯‘𝑥) = 2}) |
4 | upgrres.f | . . . . . . 7 ⊢ 𝐹 = {𝑖 ∈ dom 𝐸 ∣ 𝑁 ∉ (𝐸‘𝑖)} | |
5 | 4 | ssrab3 4016 | . . . . . 6 ⊢ 𝐹 ⊆ dom 𝐸 |
6 | 5 | a1i 11 | . . . . 5 ⊢ ((𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉) → 𝐹 ⊆ dom 𝐸) |
7 | f1ssres 6667 | . . . . 5 ⊢ ((𝐸:dom 𝐸–1-1→{𝑥 ∈ (𝒫 𝑉 ∖ {∅}) ∣ (♯‘𝑥) = 2} ∧ 𝐹 ⊆ dom 𝐸) → (𝐸 ↾ 𝐹):𝐹–1-1→{𝑥 ∈ (𝒫 𝑉 ∖ {∅}) ∣ (♯‘𝑥) = 2}) | |
8 | 3, 6, 7 | syl2an2r 681 | . . . 4 ⊢ ((𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉) → (𝐸 ↾ 𝐹):𝐹–1-1→{𝑥 ∈ (𝒫 𝑉 ∖ {∅}) ∣ (♯‘𝑥) = 2}) |
9 | usgrumgr 27492 | . . . . 5 ⊢ (𝐺 ∈ USGraph → 𝐺 ∈ UMGraph) | |
10 | 1, 2, 4 | umgrreslem 27615 | . . . . 5 ⊢ ((𝐺 ∈ UMGraph ∧ 𝑁 ∈ 𝑉) → ran (𝐸 ↾ 𝐹) ⊆ {𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2}) |
11 | 9, 10 | sylan 579 | . . . 4 ⊢ ((𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉) → ran (𝐸 ↾ 𝐹) ⊆ {𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2}) |
12 | f1ssr 6666 | . . . 4 ⊢ (((𝐸 ↾ 𝐹):𝐹–1-1→{𝑥 ∈ (𝒫 𝑉 ∖ {∅}) ∣ (♯‘𝑥) = 2} ∧ ran (𝐸 ↾ 𝐹) ⊆ {𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2}) → (𝐸 ↾ 𝐹):𝐹–1-1→{𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2}) | |
13 | 8, 11, 12 | syl2anc 583 | . . 3 ⊢ ((𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉) → (𝐸 ↾ 𝐹):𝐹–1-1→{𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2}) |
14 | ssdmres 5908 | . . . . 5 ⊢ (𝐹 ⊆ dom 𝐸 ↔ dom (𝐸 ↾ 𝐹) = 𝐹) | |
15 | 5, 14 | mpbi 229 | . . . 4 ⊢ dom (𝐸 ↾ 𝐹) = 𝐹 |
16 | f1eq2 6655 | . . . 4 ⊢ (dom (𝐸 ↾ 𝐹) = 𝐹 → ((𝐸 ↾ 𝐹):dom (𝐸 ↾ 𝐹)–1-1→{𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2} ↔ (𝐸 ↾ 𝐹):𝐹–1-1→{𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2})) | |
17 | 15, 16 | ax-mp 5 | . . 3 ⊢ ((𝐸 ↾ 𝐹):dom (𝐸 ↾ 𝐹)–1-1→{𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2} ↔ (𝐸 ↾ 𝐹):𝐹–1-1→{𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2}) |
18 | 13, 17 | sylibr 233 | . 2 ⊢ ((𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉) → (𝐸 ↾ 𝐹):dom (𝐸 ↾ 𝐹)–1-1→{𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2}) |
19 | upgrres.s | . . . 4 ⊢ 𝑆 = 〈(𝑉 ∖ {𝑁}), (𝐸 ↾ 𝐹)〉 | |
20 | opex 5378 | . . . 4 ⊢ 〈(𝑉 ∖ {𝑁}), (𝐸 ↾ 𝐹)〉 ∈ V | |
21 | 19, 20 | eqeltri 2833 | . . 3 ⊢ 𝑆 ∈ V |
22 | 1, 2, 4, 19 | uhgrspan1lem2 27611 | . . . . 5 ⊢ (Vtx‘𝑆) = (𝑉 ∖ {𝑁}) |
23 | 22 | eqcomi 2746 | . . . 4 ⊢ (𝑉 ∖ {𝑁}) = (Vtx‘𝑆) |
24 | 1, 2, 4, 19 | uhgrspan1lem3 27612 | . . . . 5 ⊢ (iEdg‘𝑆) = (𝐸 ↾ 𝐹) |
25 | 24 | eqcomi 2746 | . . . 4 ⊢ (𝐸 ↾ 𝐹) = (iEdg‘𝑆) |
26 | 23, 25 | isusgrs 27469 | . . 3 ⊢ (𝑆 ∈ V → (𝑆 ∈ USGraph ↔ (𝐸 ↾ 𝐹):dom (𝐸 ↾ 𝐹)–1-1→{𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2})) |
27 | 21, 26 | mp1i 13 | . 2 ⊢ ((𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉) → (𝑆 ∈ USGraph ↔ (𝐸 ↾ 𝐹):dom (𝐸 ↾ 𝐹)–1-1→{𝑝 ∈ 𝒫 (𝑉 ∖ {𝑁}) ∣ (♯‘𝑝) = 2})) |
28 | 18, 27 | mpbird 256 | 1 ⊢ ((𝐺 ∈ USGraph ∧ 𝑁 ∈ 𝑉) → 𝑆 ∈ USGraph) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∧ wa 395 = wceq 1539 ∈ wcel 2107 ∉ wnel 3047 {crab 3066 Vcvv 3427 ∖ cdif 3885 ⊆ wss 3888 ∅c0 4258 𝒫 cpw 4535 {csn 4563 〈cop 4569 dom cdm 5585 ran crn 5586 ↾ cres 5587 –1-1→wf1 6420 ‘cfv 6423 2c2 11974 ♯chash 13988 Vtxcvtx 27309 iEdgciedg 27310 UMGraphcumgr 27394 USGraphcusgr 27462 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1799 ax-4 1813 ax-5 1914 ax-6 1972 ax-7 2012 ax-8 2109 ax-9 2117 ax-10 2138 ax-11 2155 ax-12 2172 ax-ext 2708 ax-sep 5223 ax-nul 5230 ax-pow 5288 ax-pr 5352 ax-un 7571 ax-cnex 10874 ax-resscn 10875 ax-1cn 10876 ax-icn 10877 ax-addcl 10878 ax-addrcl 10879 ax-mulcl 10880 ax-mulrcl 10881 ax-mulcom 10882 ax-addass 10883 ax-mulass 10884 ax-distr 10885 ax-i2m1 10886 ax-1ne0 10887 ax-1rid 10888 ax-rnegex 10889 ax-rrecex 10890 ax-cnre 10891 ax-pre-lttri 10892 ax-pre-lttrn 10893 ax-pre-ltadd 10894 ax-pre-mulgt0 10895 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 844 df-3or 1086 df-3an 1087 df-tru 1542 df-fal 1552 df-ex 1784 df-nf 1788 df-sb 2069 df-mo 2539 df-eu 2568 df-clab 2715 df-cleq 2729 df-clel 2815 df-nfc 2887 df-ne 2942 df-nel 3048 df-ral 3067 df-rex 3068 df-reu 3069 df-rab 3071 df-v 3429 df-sbc 3717 df-csb 3834 df-dif 3891 df-un 3893 df-in 3895 df-ss 3905 df-pss 3907 df-nul 4259 df-if 4462 df-pw 4537 df-sn 4564 df-pr 4566 df-tp 4568 df-op 4570 df-uni 4842 df-int 4882 df-iun 4928 df-br 5076 df-opab 5138 df-mpt 5159 df-tr 5193 df-id 5485 df-eprel 5491 df-po 5499 df-so 5500 df-fr 5540 df-we 5542 df-xp 5591 df-rel 5592 df-cnv 5593 df-co 5594 df-dm 5595 df-rn 5596 df-res 5597 df-ima 5598 df-pred 6196 df-ord 6259 df-on 6260 df-lim 6261 df-suc 6262 df-iota 6381 df-fun 6425 df-fn 6426 df-f 6427 df-f1 6428 df-fo 6429 df-f1o 6430 df-fv 6431 df-riota 7217 df-ov 7263 df-oprab 7264 df-mpo 7265 df-om 7693 df-1st 7809 df-2nd 7810 df-frecs 8073 df-wrecs 8104 df-recs 8178 df-rdg 8217 df-1o 8272 df-er 8461 df-en 8697 df-dom 8698 df-sdom 8699 df-fin 8700 df-card 9644 df-pnf 10958 df-mnf 10959 df-xr 10960 df-ltxr 10961 df-le 10962 df-sub 11153 df-neg 11154 df-nn 11920 df-2 11982 df-n0 12180 df-z 12266 df-uz 12528 df-fz 13185 df-hash 13989 df-vtx 27311 df-iedg 27312 df-uhgr 27371 df-upgr 27395 df-umgr 27396 df-usgr 27464 |
This theorem is referenced by: (None) |
Copyright terms: Public domain | W3C validator |