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Mirrors > Home > MPE Home > Th. List > 1hevtxdg0 | Structured version Visualization version GIF version |
Description: The vertex degree of vertex 𝐷 in a graph 𝐺 with only one hyperedge 𝐸 is 0 if 𝐷 is not incident with the edge 𝐸. (Contributed by AV, 2-Mar-2021.) |
Ref | Expression |
---|---|
1hevtxdg0.i | ⊢ (𝜑 → (iEdg‘𝐺) = {〈𝐴, 𝐸〉}) |
1hevtxdg0.v | ⊢ (𝜑 → (Vtx‘𝐺) = 𝑉) |
1hevtxdg0.a | ⊢ (𝜑 → 𝐴 ∈ 𝑋) |
1hevtxdg0.d | ⊢ (𝜑 → 𝐷 ∈ 𝑉) |
1hevtxdg0.e | ⊢ (𝜑 → 𝐸 ∈ 𝑌) |
1hevtxdg0.n | ⊢ (𝜑 → 𝐷 ∉ 𝐸) |
Ref | Expression |
---|---|
1hevtxdg0 | ⊢ (𝜑 → ((VtxDeg‘𝐺)‘𝐷) = 0) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 1hevtxdg0.n | . . . . . . 7 ⊢ (𝜑 → 𝐷 ∉ 𝐸) | |
2 | df-nel 3045 | . . . . . . 7 ⊢ (𝐷 ∉ 𝐸 ↔ ¬ 𝐷 ∈ 𝐸) | |
3 | 1, 2 | sylib 218 | . . . . . 6 ⊢ (𝜑 → ¬ 𝐷 ∈ 𝐸) |
4 | 1hevtxdg0.i | . . . . . . . 8 ⊢ (𝜑 → (iEdg‘𝐺) = {〈𝐴, 𝐸〉}) | |
5 | 4 | fveq1d 6909 | . . . . . . 7 ⊢ (𝜑 → ((iEdg‘𝐺)‘𝐴) = ({〈𝐴, 𝐸〉}‘𝐴)) |
6 | 1hevtxdg0.a | . . . . . . . 8 ⊢ (𝜑 → 𝐴 ∈ 𝑋) | |
7 | 1hevtxdg0.e | . . . . . . . 8 ⊢ (𝜑 → 𝐸 ∈ 𝑌) | |
8 | fvsng 7200 | . . . . . . . 8 ⊢ ((𝐴 ∈ 𝑋 ∧ 𝐸 ∈ 𝑌) → ({〈𝐴, 𝐸〉}‘𝐴) = 𝐸) | |
9 | 6, 7, 8 | syl2anc 584 | . . . . . . 7 ⊢ (𝜑 → ({〈𝐴, 𝐸〉}‘𝐴) = 𝐸) |
10 | 5, 9 | eqtrd 2775 | . . . . . 6 ⊢ (𝜑 → ((iEdg‘𝐺)‘𝐴) = 𝐸) |
11 | 3, 10 | neleqtrrd 2862 | . . . . 5 ⊢ (𝜑 → ¬ 𝐷 ∈ ((iEdg‘𝐺)‘𝐴)) |
12 | fveq2 6907 | . . . . . . . . 9 ⊢ (𝑥 = 𝐴 → ((iEdg‘𝐺)‘𝑥) = ((iEdg‘𝐺)‘𝐴)) | |
13 | 12 | eleq2d 2825 | . . . . . . . 8 ⊢ (𝑥 = 𝐴 → (𝐷 ∈ ((iEdg‘𝐺)‘𝑥) ↔ 𝐷 ∈ ((iEdg‘𝐺)‘𝐴))) |
14 | 13 | notbid 318 | . . . . . . 7 ⊢ (𝑥 = 𝐴 → (¬ 𝐷 ∈ ((iEdg‘𝐺)‘𝑥) ↔ ¬ 𝐷 ∈ ((iEdg‘𝐺)‘𝐴))) |
15 | 14 | ralsng 4680 | . . . . . 6 ⊢ (𝐴 ∈ 𝑋 → (∀𝑥 ∈ {𝐴} ¬ 𝐷 ∈ ((iEdg‘𝐺)‘𝑥) ↔ ¬ 𝐷 ∈ ((iEdg‘𝐺)‘𝐴))) |
16 | 6, 15 | syl 17 | . . . . 5 ⊢ (𝜑 → (∀𝑥 ∈ {𝐴} ¬ 𝐷 ∈ ((iEdg‘𝐺)‘𝑥) ↔ ¬ 𝐷 ∈ ((iEdg‘𝐺)‘𝐴))) |
17 | 11, 16 | mpbird 257 | . . . 4 ⊢ (𝜑 → ∀𝑥 ∈ {𝐴} ¬ 𝐷 ∈ ((iEdg‘𝐺)‘𝑥)) |
18 | 4 | dmeqd 5919 | . . . . 5 ⊢ (𝜑 → dom (iEdg‘𝐺) = dom {〈𝐴, 𝐸〉}) |
19 | dmsnopg 6235 | . . . . . 6 ⊢ (𝐸 ∈ 𝑌 → dom {〈𝐴, 𝐸〉} = {𝐴}) | |
20 | 7, 19 | syl 17 | . . . . 5 ⊢ (𝜑 → dom {〈𝐴, 𝐸〉} = {𝐴}) |
21 | 18, 20 | eqtrd 2775 | . . . 4 ⊢ (𝜑 → dom (iEdg‘𝐺) = {𝐴}) |
22 | 17, 21 | raleqtrrdv 3328 | . . 3 ⊢ (𝜑 → ∀𝑥 ∈ dom (iEdg‘𝐺) ¬ 𝐷 ∈ ((iEdg‘𝐺)‘𝑥)) |
23 | ralnex 3070 | . . 3 ⊢ (∀𝑥 ∈ dom (iEdg‘𝐺) ¬ 𝐷 ∈ ((iEdg‘𝐺)‘𝑥) ↔ ¬ ∃𝑥 ∈ dom (iEdg‘𝐺)𝐷 ∈ ((iEdg‘𝐺)‘𝑥)) | |
24 | 22, 23 | sylib 218 | . 2 ⊢ (𝜑 → ¬ ∃𝑥 ∈ dom (iEdg‘𝐺)𝐷 ∈ ((iEdg‘𝐺)‘𝑥)) |
25 | 1hevtxdg0.d | . . . 4 ⊢ (𝜑 → 𝐷 ∈ 𝑉) | |
26 | 1hevtxdg0.v | . . . . 5 ⊢ (𝜑 → (Vtx‘𝐺) = 𝑉) | |
27 | 26 | eleq2d 2825 | . . . 4 ⊢ (𝜑 → (𝐷 ∈ (Vtx‘𝐺) ↔ 𝐷 ∈ 𝑉)) |
28 | 25, 27 | mpbird 257 | . . 3 ⊢ (𝜑 → 𝐷 ∈ (Vtx‘𝐺)) |
29 | eqid 2735 | . . . 4 ⊢ (Vtx‘𝐺) = (Vtx‘𝐺) | |
30 | eqid 2735 | . . . 4 ⊢ (iEdg‘𝐺) = (iEdg‘𝐺) | |
31 | eqid 2735 | . . . 4 ⊢ (VtxDeg‘𝐺) = (VtxDeg‘𝐺) | |
32 | 29, 30, 31 | vtxd0nedgb 29521 | . . 3 ⊢ (𝐷 ∈ (Vtx‘𝐺) → (((VtxDeg‘𝐺)‘𝐷) = 0 ↔ ¬ ∃𝑥 ∈ dom (iEdg‘𝐺)𝐷 ∈ ((iEdg‘𝐺)‘𝑥))) |
33 | 28, 32 | syl 17 | . 2 ⊢ (𝜑 → (((VtxDeg‘𝐺)‘𝐷) = 0 ↔ ¬ ∃𝑥 ∈ dom (iEdg‘𝐺)𝐷 ∈ ((iEdg‘𝐺)‘𝑥))) |
34 | 24, 33 | mpbird 257 | 1 ⊢ (𝜑 → ((VtxDeg‘𝐺)‘𝐷) = 0) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ↔ wb 206 = wceq 1537 ∈ wcel 2106 ∉ wnel 3044 ∀wral 3059 ∃wrex 3068 {csn 4631 〈cop 4637 dom cdm 5689 ‘cfv 6563 0cc0 11153 Vtxcvtx 29028 iEdgciedg 29029 VtxDegcvtxdg 29498 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1792 ax-4 1806 ax-5 1908 ax-6 1965 ax-7 2005 ax-8 2108 ax-9 2116 ax-10 2139 ax-11 2155 ax-12 2175 ax-ext 2706 ax-rep 5285 ax-sep 5302 ax-nul 5312 ax-pow 5371 ax-pr 5438 ax-un 7754 ax-cnex 11209 ax-resscn 11210 ax-1cn 11211 ax-icn 11212 ax-addcl 11213 ax-addrcl 11214 ax-mulcl 11215 ax-mulrcl 11216 ax-mulcom 11217 ax-addass 11218 ax-mulass 11219 ax-distr 11220 ax-i2m1 11221 ax-1ne0 11222 ax-1rid 11223 ax-rnegex 11224 ax-rrecex 11225 ax-cnre 11226 ax-pre-lttri 11227 ax-pre-lttrn 11228 ax-pre-ltadd 11229 ax-pre-mulgt0 11230 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3or 1087 df-3an 1088 df-tru 1540 df-fal 1550 df-ex 1777 df-nf 1781 df-sb 2063 df-mo 2538 df-eu 2567 df-clab 2713 df-cleq 2727 df-clel 2814 df-nfc 2890 df-ne 2939 df-nel 3045 df-ral 3060 df-rex 3069 df-reu 3379 df-rab 3434 df-v 3480 df-sbc 3792 df-csb 3909 df-dif 3966 df-un 3968 df-in 3970 df-ss 3980 df-pss 3983 df-nul 4340 df-if 4532 df-pw 4607 df-sn 4632 df-pr 4634 df-op 4638 df-uni 4913 df-int 4952 df-iun 4998 df-br 5149 df-opab 5211 df-mpt 5232 df-tr 5266 df-id 5583 df-eprel 5589 df-po 5597 df-so 5598 df-fr 5641 df-we 5643 df-xp 5695 df-rel 5696 df-cnv 5697 df-co 5698 df-dm 5699 df-rn 5700 df-res 5701 df-ima 5702 df-pred 6323 df-ord 6389 df-on 6390 df-lim 6391 df-suc 6392 df-iota 6516 df-fun 6565 df-fn 6566 df-f 6567 df-f1 6568 df-fo 6569 df-f1o 6570 df-fv 6571 df-riota 7388 df-ov 7434 df-oprab 7435 df-mpo 7436 df-om 7888 df-1st 8013 df-2nd 8014 df-frecs 8305 df-wrecs 8336 df-recs 8410 df-rdg 8449 df-1o 8505 df-er 8744 df-en 8985 df-dom 8986 df-sdom 8987 df-fin 8988 df-card 9977 df-pnf 11295 df-mnf 11296 df-xr 11297 df-ltxr 11298 df-le 11299 df-sub 11492 df-neg 11493 df-nn 12265 df-n0 12525 df-xnn0 12598 df-z 12612 df-uz 12877 df-xadd 13153 df-fz 13545 df-hash 14367 df-vtxdg 29499 |
This theorem is referenced by: p1evtxdeq 29546 eupth2lem3lem6 30262 |
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