![]() |
Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > frgrwopreglem4 | Structured version Visualization version GIF version |
Description: Lemma 4 for frgrwopreg 30205. In a friendship graph each vertex with degree 𝐾 is connected with any vertex with degree other than 𝐾. This corresponds to statement 4 in [Huneke] p. 2: "By the first claim, every vertex in A is adjacent to every vertex in B.". (Contributed by Alexander van der Vekens, 30-Dec-2017.) (Revised by AV, 10-May-2021.) (Proof shortened by AV, 4-Feb-2022.) |
Ref | Expression |
---|---|
frgrwopreg.v | ⊢ 𝑉 = (Vtx‘𝐺) |
frgrwopreg.d | ⊢ 𝐷 = (VtxDeg‘𝐺) |
frgrwopreg.a | ⊢ 𝐴 = {𝑥 ∈ 𝑉 ∣ (𝐷‘𝑥) = 𝐾} |
frgrwopreg.b | ⊢ 𝐵 = (𝑉 ∖ 𝐴) |
frgrwopreg.e | ⊢ 𝐸 = (Edg‘𝐺) |
Ref | Expression |
---|---|
frgrwopreglem4 | ⊢ (𝐺 ∈ FriendGraph → ∀𝑎 ∈ 𝐴 ∀𝑏 ∈ 𝐵 {𝑎, 𝑏} ∈ 𝐸) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpl 481 | . . 3 ⊢ ((𝐺 ∈ FriendGraph ∧ (𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵)) → 𝐺 ∈ FriendGraph ) | |
2 | elrabi 3673 | . . . . . 6 ⊢ (𝑎 ∈ {𝑥 ∈ 𝑉 ∣ (𝐷‘𝑥) = 𝐾} → 𝑎 ∈ 𝑉) | |
3 | frgrwopreg.a | . . . . . 6 ⊢ 𝐴 = {𝑥 ∈ 𝑉 ∣ (𝐷‘𝑥) = 𝐾} | |
4 | 2, 3 | eleq2s 2843 | . . . . 5 ⊢ (𝑎 ∈ 𝐴 → 𝑎 ∈ 𝑉) |
5 | eldifi 4123 | . . . . . 6 ⊢ (𝑏 ∈ (𝑉 ∖ 𝐴) → 𝑏 ∈ 𝑉) | |
6 | frgrwopreg.b | . . . . . 6 ⊢ 𝐵 = (𝑉 ∖ 𝐴) | |
7 | 5, 6 | eleq2s 2843 | . . . . 5 ⊢ (𝑏 ∈ 𝐵 → 𝑏 ∈ 𝑉) |
8 | 4, 7 | anim12i 611 | . . . 4 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) |
9 | 8 | adantl 480 | . . 3 ⊢ ((𝐺 ∈ FriendGraph ∧ (𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵)) → (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉)) |
10 | frgrwopreg.v | . . . . 5 ⊢ 𝑉 = (Vtx‘𝐺) | |
11 | frgrwopreg.d | . . . . 5 ⊢ 𝐷 = (VtxDeg‘𝐺) | |
12 | 10, 11, 3, 6 | frgrwopreglem3 30196 | . . . 4 ⊢ ((𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵) → (𝐷‘𝑎) ≠ (𝐷‘𝑏)) |
13 | 12 | adantl 480 | . . 3 ⊢ ((𝐺 ∈ FriendGraph ∧ (𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵)) → (𝐷‘𝑎) ≠ (𝐷‘𝑏)) |
14 | frgrwopreg.e | . . . 4 ⊢ 𝐸 = (Edg‘𝐺) | |
15 | 10, 11, 14 | frgrwopreglem4a 30192 | . . 3 ⊢ ((𝐺 ∈ FriendGraph ∧ (𝑎 ∈ 𝑉 ∧ 𝑏 ∈ 𝑉) ∧ (𝐷‘𝑎) ≠ (𝐷‘𝑏)) → {𝑎, 𝑏} ∈ 𝐸) |
16 | 1, 9, 13, 15 | syl3anc 1368 | . 2 ⊢ ((𝐺 ∈ FriendGraph ∧ (𝑎 ∈ 𝐴 ∧ 𝑏 ∈ 𝐵)) → {𝑎, 𝑏} ∈ 𝐸) |
17 | 16 | ralrimivva 3190 | 1 ⊢ (𝐺 ∈ FriendGraph → ∀𝑎 ∈ 𝐴 ∀𝑏 ∈ 𝐵 {𝑎, 𝑏} ∈ 𝐸) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 394 = wceq 1533 ∈ wcel 2098 ≠ wne 2929 ∀wral 3050 {crab 3418 ∖ cdif 3941 {cpr 4632 ‘cfv 6549 Vtxcvtx 28881 Edgcedg 28932 VtxDegcvtxdg 29351 FriendGraph cfrgr 30140 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-10 2129 ax-11 2146 ax-12 2166 ax-ext 2696 ax-rep 5286 ax-sep 5300 ax-nul 5307 ax-pow 5365 ax-pr 5429 ax-un 7741 ax-cnex 11196 ax-resscn 11197 ax-1cn 11198 ax-icn 11199 ax-addcl 11200 ax-addrcl 11201 ax-mulcl 11202 ax-mulrcl 11203 ax-mulcom 11204 ax-addass 11205 ax-mulass 11206 ax-distr 11207 ax-i2m1 11208 ax-1ne0 11209 ax-1rid 11210 ax-rnegex 11211 ax-rrecex 11212 ax-cnre 11213 ax-pre-lttri 11214 ax-pre-lttrn 11215 ax-pre-ltadd 11216 ax-pre-mulgt0 11217 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 846 df-3or 1085 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-nf 1778 df-sb 2060 df-mo 2528 df-eu 2557 df-clab 2703 df-cleq 2717 df-clel 2802 df-nfc 2877 df-ne 2930 df-nel 3036 df-ral 3051 df-rex 3060 df-rmo 3363 df-reu 3364 df-rab 3419 df-v 3463 df-sbc 3774 df-csb 3890 df-dif 3947 df-un 3949 df-in 3951 df-ss 3961 df-pss 3964 df-nul 4323 df-if 4531 df-pw 4606 df-sn 4631 df-pr 4633 df-op 4637 df-uni 4910 df-int 4951 df-iun 4999 df-br 5150 df-opab 5212 df-mpt 5233 df-tr 5267 df-id 5576 df-eprel 5582 df-po 5590 df-so 5591 df-fr 5633 df-we 5635 df-xp 5684 df-rel 5685 df-cnv 5686 df-co 5687 df-dm 5688 df-rn 5689 df-res 5690 df-ima 5691 df-pred 6307 df-ord 6374 df-on 6375 df-lim 6376 df-suc 6377 df-iota 6501 df-fun 6551 df-fn 6552 df-f 6553 df-f1 6554 df-fo 6555 df-f1o 6556 df-fv 6557 df-riota 7375 df-ov 7422 df-oprab 7423 df-mpo 7424 df-om 7872 df-1st 7994 df-2nd 7995 df-frecs 8287 df-wrecs 8318 df-recs 8392 df-rdg 8431 df-1o 8487 df-2o 8488 df-oadd 8491 df-er 8725 df-en 8965 df-dom 8966 df-sdom 8967 df-fin 8968 df-dju 9926 df-card 9964 df-pnf 11282 df-mnf 11283 df-xr 11284 df-ltxr 11285 df-le 11286 df-sub 11478 df-neg 11479 df-nn 12246 df-2 12308 df-n0 12506 df-xnn0 12578 df-z 12592 df-uz 12856 df-xadd 13128 df-fz 13520 df-hash 14326 df-edg 28933 df-uhgr 28943 df-ushgr 28944 df-upgr 28967 df-umgr 28968 df-uspgr 29035 df-usgr 29036 df-nbgr 29218 df-vtxdg 29352 df-frgr 30141 |
This theorem is referenced by: frgrwopregasn 30198 frgrwopregbsn 30199 frgrwopreglem5ALT 30204 |
Copyright terms: Public domain | W3C validator |