Theorem incistruhgr 28866

Description: An incidence structure ⟨𝑃, 𝐿, 𝐼⟩ "where 𝑃 is a set whose elements are called points, 𝐿 is a distinct set whose elements are called lines and 𝐼 ⊆ (𝑃 × 𝐿) is the incidence relation" (see Wikipedia "Incidence structure" (24-Oct-2020), https://en.wikipedia.org/wiki/Incidence_structure) implies an undirected hypergraph, if the incidence relation is right-total (to exclude empty edges). The points become the vertices, and the edge function is derived from the incidence relation by mapping each line ("edge") to the set of vertices incident to the line/edge. With 𝑃 = (Base‘𝑆) and by defining two new slots for lines and incidence relations (analogous to LineG and Itv) and enhancing the definition of iEdg accordingly, it would even be possible to express that a corresponding incidence structure is an undirected hypergraph. By choosing the incident relation appropriately, other kinds of undirected graphs (pseudographs, multigraphs, simple graphs, etc.) could be defined. (Contributed by AV, 24-Oct-2020.)

Hypotheses

Ref	Expression
incistruhgr.v	⊢ 𝑉 = (Vtx‘𝐺)
incistruhgr.e	⊢ 𝐸 = (iEdg‘𝐺)

Assertion

Ref	Expression
incistruhgr	⊢ ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑃 × 𝐿) ∧ ran 𝐼 = 𝐿) → ((𝑉 = 𝑃 ∧ 𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒})) → 𝐺 ∈ UHGraph))

Distinct variable groups:   𝑒,𝐸   𝑒,𝐺   𝑒,𝐼,𝑣   𝑒,𝐿,𝑣   𝑃,𝑒,𝑣   𝑒,𝑉,𝑣   𝑒,𝑊

Allowed substitution hints:   𝐸(𝑣)   𝐺(𝑣)   𝑊(𝑣)

Proof of Theorem incistruhgr

Step	Hyp	Ref	Expression
1		rabeq 3441	. . . . . . . . 9 ⊢ (𝑉 = 𝑃 → {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} = {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒})
2	1	mpteq2dv 5244	. . . . . . . 8 ⊢ (𝑉 = 𝑃 → (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒}))
3	2	eqeq2d 2738	. . . . . . 7 ⊢ (𝑉 = 𝑃 → (𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) ↔ 𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒})))
4		xpeq1 5686	. . . . . . . . 9 ⊢ (𝑉 = 𝑃 → (𝑉 × 𝐿) = (𝑃 × 𝐿))
5	4	sseq2d 4010	. . . . . . . 8 ⊢ (𝑉 = 𝑃 → (𝐼 ⊆ (𝑉 × 𝐿) ↔ 𝐼 ⊆ (𝑃 × 𝐿)))
6	5	3anbi2d 1438	. . . . . . 7 ⊢ (𝑉 = 𝑃 → ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) ↔ (𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑃 × 𝐿) ∧ ran 𝐼 = 𝐿)))
7	3, 6	anbi12d 630	. . . . . 6 ⊢ (𝑉 = 𝑃 → ((𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) ∧ (𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿)) ↔ (𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒}) ∧ (𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑃 × 𝐿) ∧ ran 𝐼 = 𝐿))))
8		dmeq 5900	. . . . . . . . 9 ⊢ (𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) → dom 𝐸 = dom (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}))
9		incistruhgr.v	. . . . . . . . . . . 12 ⊢ 𝑉 = (Vtx‘𝐺)
10	9	fvexi 6905	. . . . . . . . . . 11 ⊢ 𝑉 ∈ V
11	10	rabex 5328	. . . . . . . . . 10 ⊢ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ∈ V
12		eqid 2727	. . . . . . . . . 10 ⊢ (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒})
13	11, 12	dmmpti 6693	. . . . . . . . 9 ⊢ dom (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) = 𝐿
14	8, 13	eqtrdi 2783	. . . . . . . 8 ⊢ (𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) → dom 𝐸 = 𝐿)
15		ssrab2 4073	. . . . . . . . . . . . 13 ⊢ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ⊆ 𝑉
16	15	a1i 11	. . . . . . . . . . . 12 ⊢ (((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) ∧ 𝑒 ∈ 𝐿) → {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ⊆ 𝑉)
17	11	elpw 4602	. . . . . . . . . . . 12 ⊢ ({𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ∈ 𝒫 𝑉 ↔ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ⊆ 𝑉)
18	16, 17	sylibr 233	. . . . . . . . . . 11 ⊢ (((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) ∧ 𝑒 ∈ 𝐿) → {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ∈ 𝒫 𝑉)
19		eleq2 2817	. . . . . . . . . . . . . . . 16 ⊢ (ran 𝐼 = 𝐿 → (𝑒 ∈ ran 𝐼 ↔ 𝑒 ∈ 𝐿))
20	19	3ad2ant3 1133	. . . . . . . . . . . . . . 15 ⊢ ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) → (𝑒 ∈ ran 𝐼 ↔ 𝑒 ∈ 𝐿))
21		ssrelrn 5891	. . . . . . . . . . . . . . . . 17 ⊢ ((𝐼 ⊆ (𝑉 × 𝐿) ∧ 𝑒 ∈ ran 𝐼) → ∃𝑣 ∈ 𝑉 𝑣𝐼𝑒)
22	21	ex 412	. . . . . . . . . . . . . . . 16 ⊢ (𝐼 ⊆ (𝑉 × 𝐿) → (𝑒 ∈ ran 𝐼 → ∃𝑣 ∈ 𝑉 𝑣𝐼𝑒))
23	22	3ad2ant2 1132	. . . . . . . . . . . . . . 15 ⊢ ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) → (𝑒 ∈ ran 𝐼 → ∃𝑣 ∈ 𝑉 𝑣𝐼𝑒))
24	20, 23	sylbird 260	. . . . . . . . . . . . . 14 ⊢ ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) → (𝑒 ∈ 𝐿 → ∃𝑣 ∈ 𝑉 𝑣𝐼𝑒))
25	24	imp 406	. . . . . . . . . . . . 13 ⊢ (((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) ∧ 𝑒 ∈ 𝐿) → ∃𝑣 ∈ 𝑉 𝑣𝐼𝑒)
26		df-ne 2936	. . . . . . . . . . . . . 14 ⊢ ({𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ≠ ∅ ↔ ¬ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} = ∅)
27		rabn0 4381	. . . . . . . . . . . . . 14 ⊢ ({𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ≠ ∅ ↔ ∃𝑣 ∈ 𝑉 𝑣𝐼𝑒)
28	26, 27	bitr3i 277	. . . . . . . . . . . . 13 ⊢ (¬ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} = ∅ ↔ ∃𝑣 ∈ 𝑉 𝑣𝐼𝑒)
29	25, 28	sylibr 233	. . . . . . . . . . . 12 ⊢ (((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) ∧ 𝑒 ∈ 𝐿) → ¬ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} = ∅)
30	11	elsn 4639	. . . . . . . . . . . 12 ⊢ ({𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ∈ {∅} ↔ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} = ∅)
31	29, 30	sylnibr 329	. . . . . . . . . . 11 ⊢ (((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) ∧ 𝑒 ∈ 𝐿) → ¬ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ∈ {∅})
32	18, 31	eldifd 3955	. . . . . . . . . 10 ⊢ (((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) ∧ 𝑒 ∈ 𝐿) → {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒} ∈ (𝒫 𝑉 ∖ {∅}))
33	32	fmpttd 7119	. . . . . . . . 9 ⊢ ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) → (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}):𝐿⟶(𝒫 𝑉 ∖ {∅}))
34		simpl 482	. . . . . . . . . 10 ⊢ ((𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) ∧ dom 𝐸 = 𝐿) → 𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}))
35		simpr 484	. . . . . . . . . 10 ⊢ ((𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) ∧ dom 𝐸 = 𝐿) → dom 𝐸 = 𝐿)
36	34, 35	feq12d 6704	. . . . . . . . 9 ⊢ ((𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) ∧ dom 𝐸 = 𝐿) → (𝐸:dom 𝐸⟶(𝒫 𝑉 ∖ {∅}) ↔ (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}):𝐿⟶(𝒫 𝑉 ∖ {∅})))
37	33, 36	imbitrrid 245	. . . . . . . 8 ⊢ ((𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) ∧ dom 𝐸 = 𝐿) → ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) → 𝐸:dom 𝐸⟶(𝒫 𝑉 ∖ {∅})))
38	14, 37	mpdan 686	. . . . . . 7 ⊢ (𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) → ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿) → 𝐸:dom 𝐸⟶(𝒫 𝑉 ∖ {∅})))
39	38	imp 406	. . . . . 6 ⊢ ((𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑉 ∣ 𝑣𝐼𝑒}) ∧ (𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑉 × 𝐿) ∧ ran 𝐼 = 𝐿)) → 𝐸:dom 𝐸⟶(𝒫 𝑉 ∖ {∅}))
40	7, 39	syl6bir 254	. . . . 5 ⊢ (𝑉 = 𝑃 → ((𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒}) ∧ (𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑃 × 𝐿) ∧ ran 𝐼 = 𝐿)) → 𝐸:dom 𝐸⟶(𝒫 𝑉 ∖ {∅})))
41	40	expdimp 452	. . . 4 ⊢ ((𝑉 = 𝑃 ∧ 𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒})) → ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑃 × 𝐿) ∧ ran 𝐼 = 𝐿) → 𝐸:dom 𝐸⟶(𝒫 𝑉 ∖ {∅})))
42	41	impcom 407	. . 3 ⊢ (((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑃 × 𝐿) ∧ ran 𝐼 = 𝐿) ∧ (𝑉 = 𝑃 ∧ 𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒}))) → 𝐸:dom 𝐸⟶(𝒫 𝑉 ∖ {∅}))
43		incistruhgr.e	. . . . . 6 ⊢ 𝐸 = (iEdg‘𝐺)
44	9, 43	isuhgr 28847	. . . . 5 ⊢ (𝐺 ∈ 𝑊 → (𝐺 ∈ UHGraph ↔ 𝐸:dom 𝐸⟶(𝒫 𝑉 ∖ {∅})))
45	44	3ad2ant1 1131	. . . 4 ⊢ ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑃 × 𝐿) ∧ ran 𝐼 = 𝐿) → (𝐺 ∈ UHGraph ↔ 𝐸:dom 𝐸⟶(𝒫 𝑉 ∖ {∅})))
46	45	adantr 480	. . 3 ⊢ (((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑃 × 𝐿) ∧ ran 𝐼 = 𝐿) ∧ (𝑉 = 𝑃 ∧ 𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒}))) → (𝐺 ∈ UHGraph ↔ 𝐸:dom 𝐸⟶(𝒫 𝑉 ∖ {∅})))
47	42, 46	mpbird 257	. 2 ⊢ (((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑃 × 𝐿) ∧ ran 𝐼 = 𝐿) ∧ (𝑉 = 𝑃 ∧ 𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒}))) → 𝐺 ∈ UHGraph)
48	47	ex 412	1 ⊢ ((𝐺 ∈ 𝑊 ∧ 𝐼 ⊆ (𝑃 × 𝐿) ∧ ran 𝐼 = 𝐿) → ((𝑉 = 𝑃 ∧ 𝐸 = (𝑒 ∈ 𝐿 ↦ {𝑣 ∈ 𝑃 ∣ 𝑣𝐼𝑒})) → 𝐺 ∈ UHGraph))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 205   ∧ wa 395   ∧ w3a 1085   = wceq 1534   ∈ wcel 2099   ≠ wne 2935  ∃wrex 3065  {crab 3427   ∖ cdif 3941   ⊆ wss 3944  ∅c0 4318  𝒫 cpw 4598  {csn 4624   class class class wbr 5142   ↦ cmpt 5225   × cxp 5670  dom cdm 5672  ran crn 5673  ⟶wf 6538  ‘cfv 6542  Vtxcvtx 28783  iEdgciedg 28784  UHGraphcuhgr 28843

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1790  ax-4 1804  ax-5 1906  ax-6 1964  ax-7 2004  ax-8 2101  ax-9 2109  ax-10 2130  ax-11 2147  ax-12 2164  ax-ext 2698  ax-sep 5293  ax-nul 5300  ax-pr 5423

This theorem depends on definitions:  df-bi 206  df-an 396  df-or 847  df-3an 1087  df-tru 1537  df-fal 1547  df-ex 1775  df-nf 1779  df-sb 2061  df-mo 2529  df-eu 2558  df-clab 2705  df-cleq 2719  df-clel 2805  df-nfc 2880  df-ne 2936  df-ral 3057  df-rex 3066  df-rab 3428  df-v 3471  df-sbc 3775  df-dif 3947  df-un 3949  df-in 3951  df-ss 3961  df-nul 4319  df-if 4525  df-pw 4600  df-sn 4625  df-pr 4627  df-op 4631  df-uni 4904  df-br 5143  df-opab 5205  df-mpt 5226  df-id 5570  df-xp 5678  df-rel 5679  df-cnv 5680  df-co 5681  df-dm 5682  df-rn 5683  df-res 5684  df-ima 5685  df-iota 6494  df-fun 6544  df-fn 6545  df-f 6546  df-fv 6550  df-uhgr 28845

This theorem is referenced by: (None)