Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > MPE Home > Th. List > frgraregord13 | Structured version Visualization version GIF version |
Description: If a nonempty finite friendship graph is k-regular, then it must have order 1 or 3. Special case of frgraregord013 26645. (Contributed by Alexander van der Vekens, 9-Oct-2018.) |
Ref | Expression |
---|---|
frgraregord13 | ⊢ (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpl1 1057 | . . 3 ⊢ (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → 𝑉 FriendGrph 𝐸) | |
2 | simpl2 1058 | . . 3 ⊢ (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → 𝑉 ∈ Fin) | |
3 | simpr 476 | . . 3 ⊢ (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → 〈𝑉, 𝐸〉 RegUSGrph 𝐾) | |
4 | frgraregord013 26645 | . . 3 ⊢ ((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → ((#‘𝑉) = 0 ∨ (#‘𝑉) = 1 ∨ (#‘𝑉) = 3)) | |
5 | 1, 2, 3, 4 | syl3anc 1318 | . 2 ⊢ (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → ((#‘𝑉) = 0 ∨ (#‘𝑉) = 1 ∨ (#‘𝑉) = 3)) |
6 | hasheq0 13015 | . . . . . . . . . 10 ⊢ (𝑉 ∈ Fin → ((#‘𝑉) = 0 ↔ 𝑉 = ∅)) | |
7 | 6 | bicomd 212 | . . . . . . . . 9 ⊢ (𝑉 ∈ Fin → (𝑉 = ∅ ↔ (#‘𝑉) = 0)) |
8 | 7 | necon3bid 2826 | . . . . . . . 8 ⊢ (𝑉 ∈ Fin → (𝑉 ≠ ∅ ↔ (#‘𝑉) ≠ 0)) |
9 | eqneqall 2793 | . . . . . . . . 9 ⊢ ((#‘𝑉) = 0 → ((#‘𝑉) ≠ 0 → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3))) | |
10 | 9 | com12 32 | . . . . . . . 8 ⊢ ((#‘𝑉) ≠ 0 → ((#‘𝑉) = 0 → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3))) |
11 | 8, 10 | syl6bi 242 | . . . . . . 7 ⊢ (𝑉 ∈ Fin → (𝑉 ≠ ∅ → ((#‘𝑉) = 0 → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3)))) |
12 | 11 | a1i 11 | . . . . . 6 ⊢ (𝑉 FriendGrph 𝐸 → (𝑉 ∈ Fin → (𝑉 ≠ ∅ → ((#‘𝑉) = 0 → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3))))) |
13 | 12 | 3imp 1249 | . . . . 5 ⊢ ((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) → ((#‘𝑉) = 0 → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3))) |
14 | 13 | adantr 480 | . . . 4 ⊢ (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → ((#‘𝑉) = 0 → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3))) |
15 | 14 | com12 32 | . . 3 ⊢ ((#‘𝑉) = 0 → (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3))) |
16 | orc 399 | . . . 4 ⊢ ((#‘𝑉) = 1 → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3)) | |
17 | 16 | a1d 25 | . . 3 ⊢ ((#‘𝑉) = 1 → (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3))) |
18 | olc 398 | . . . 4 ⊢ ((#‘𝑉) = 3 → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3)) | |
19 | 18 | a1d 25 | . . 3 ⊢ ((#‘𝑉) = 3 → (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3))) |
20 | 15, 17, 19 | 3jaoi 1383 | . 2 ⊢ (((#‘𝑉) = 0 ∨ (#‘𝑉) = 1 ∨ (#‘𝑉) = 3) → (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3))) |
21 | 5, 20 | mpcom 37 | 1 ⊢ (((𝑉 FriendGrph 𝐸 ∧ 𝑉 ∈ Fin ∧ 𝑉 ≠ ∅) ∧ 〈𝑉, 𝐸〉 RegUSGrph 𝐾) → ((#‘𝑉) = 1 ∨ (#‘𝑉) = 3)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∨ wo 382 ∧ wa 383 ∨ w3o 1030 ∧ w3a 1031 = wceq 1475 ∈ wcel 1977 ≠ wne 2780 ∅c0 3874 〈cop 4131 class class class wbr 4583 ‘cfv 5804 Fincfn 7841 0cc0 9815 1c1 9816 3c3 10948 #chash 12979 RegUSGrph crusgra 26450 FriendGrph cfrgra 26515 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 ax-6 1875 ax-7 1922 ax-8 1979 ax-9 1986 ax-10 2006 ax-11 2021 ax-12 2034 ax-13 2234 ax-ext 2590 ax-rep 4699 ax-sep 4709 ax-nul 4717 ax-pow 4769 ax-pr 4833 ax-un 6847 ax-inf2 8421 ax-cnex 9871 ax-resscn 9872 ax-1cn 9873 ax-icn 9874 ax-addcl 9875 ax-addrcl 9876 ax-mulcl 9877 ax-mulrcl 9878 ax-mulcom 9879 ax-addass 9880 ax-mulass 9881 ax-distr 9882 ax-i2m1 9883 ax-1ne0 9884 ax-1rid 9885 ax-rnegex 9886 ax-rrecex 9887 ax-cnre 9888 ax-pre-lttri 9889 ax-pre-lttrn 9890 ax-pre-ltadd 9891 ax-pre-mulgt0 9892 ax-pre-sup 9893 |
This theorem depends on definitions: df-bi 196 df-or 384 df-an 385 df-3or 1032 df-3an 1033 df-tru 1478 df-fal 1481 df-ex 1696 df-nf 1701 df-sb 1868 df-eu 2462 df-mo 2463 df-clab 2597 df-cleq 2603 df-clel 2606 df-nfc 2740 df-ne 2782 df-nel 2783 df-ral 2901 df-rex 2902 df-reu 2903 df-rmo 2904 df-rab 2905 df-v 3175 df-sbc 3403 df-csb 3500 df-dif 3543 df-un 3545 df-in 3547 df-ss 3554 df-pss 3556 df-nul 3875 df-if 4037 df-pw 4110 df-sn 4126 df-pr 4128 df-tp 4130 df-op 4132 df-ot 4134 df-uni 4373 df-int 4411 df-iun 4457 df-disj 4554 df-br 4584 df-opab 4644 df-mpt 4645 df-tr 4681 df-eprel 4949 df-id 4953 df-po 4959 df-so 4960 df-fr 4997 df-se 4998 df-we 4999 df-xp 5044 df-rel 5045 df-cnv 5046 df-co 5047 df-dm 5048 df-rn 5049 df-res 5050 df-ima 5051 df-pred 5597 df-ord 5643 df-on 5644 df-lim 5645 df-suc 5646 df-iota 5768 df-fun 5806 df-fn 5807 df-f 5808 df-f1 5809 df-fo 5810 df-f1o 5811 df-fv 5812 df-isom 5813 df-riota 6511 df-ov 6552 df-oprab 6553 df-mpt2 6554 df-om 6958 df-1st 7059 df-2nd 7060 df-wrecs 7294 df-recs 7355 df-rdg 7393 df-1o 7447 df-2o 7448 df-oadd 7451 df-er 7629 df-ec 7631 df-qs 7635 df-map 7746 df-pm 7747 df-en 7842 df-dom 7843 df-sdom 7844 df-fin 7845 df-sup 8231 df-inf 8232 df-oi 8298 df-card 8648 df-cda 8873 df-pnf 9955 df-mnf 9956 df-xr 9957 df-ltxr 9958 df-le 9959 df-sub 10147 df-neg 10148 df-div 10564 df-nn 10898 df-2 10956 df-3 10957 df-n0 11170 df-xnn0 11241 df-z 11255 df-uz 11564 df-rp 11709 df-xadd 11823 df-ico 12052 df-fz 12198 df-fzo 12335 df-fl 12455 df-mod 12531 df-seq 12664 df-exp 12723 df-hash 12980 df-word 13154 df-lsw 13155 df-concat 13156 df-s1 13157 df-substr 13158 df-reps 13161 df-csh 13386 df-s2 13444 df-cj 13687 df-re 13688 df-im 13689 df-sqrt 13823 df-abs 13824 df-clim 14067 df-sum 14265 df-dvds 14822 df-gcd 15055 df-prm 15224 df-phi 15309 df-usgra 25862 df-nbgra 25949 df-wlk 26036 df-trail 26037 df-pth 26038 df-spth 26039 df-wlkon 26042 df-spthon 26045 df-wwlk 26207 df-wwlkn 26208 df-clwwlk 26279 df-clwwlkn 26280 df-2wlkonot 26385 df-2spthonot 26387 df-2spthsot 26388 df-vdgr 26421 df-rgra 26451 df-rusgra 26452 df-frgra 26516 |
This theorem is referenced by: frgraogt3nreg 26647 |
Copyright terms: Public domain | W3C validator |