Theorem isubgr3stgrlem3 47870

Description: Lemma 3 for isubgr3stgr 47877. (Contributed by AV, 17-Sep-2025.)

Hypotheses

Ref	Expression
isubgr3stgr.v	⊢ 𝑉 = (Vtx‘𝐺)
isubgr3stgr.u	⊢ 𝑈 = (𝐺 NeighbVtx 𝑋)
isubgr3stgr.c	⊢ 𝐶 = (𝐺 ClNeighbVtx 𝑋)
isubgr3stgr.n	⊢ 𝑁 ∈ ℕ0
isubgr3stgr.s	⊢ 𝑆 = (StarGr‘𝑁)
isubgr3stgr.w	⊢ 𝑊 = (Vtx‘𝑆)

Assertion

Ref	Expression
isubgr3stgrlem3	⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → ∃𝑔(𝑔:𝐶–1-1-onto→𝑊 ∧ (𝑔‘𝑋) = 0))

Distinct variable groups:   𝐶,𝑔   𝑔,𝑊   𝑔,𝑋

Allowed substitution hints:   𝑆(𝑔)   𝑈(𝑔)   𝐺(𝑔)   𝑁(𝑔)   𝑉(𝑔)

Proof of Theorem isubgr3stgrlem3

Dummy variable 𝑓 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		isubgr3stgr.v	. . 3 ⊢ 𝑉 = (Vtx‘𝐺)
2		isubgr3stgr.u	. . 3 ⊢ 𝑈 = (𝐺 NeighbVtx 𝑋)
3		isubgr3stgr.c	. . 3 ⊢ 𝐶 = (𝐺 ClNeighbVtx 𝑋)
4		isubgr3stgr.n	. . 3 ⊢ 𝑁 ∈ ℕ0
5		isubgr3stgr.s	. . 3 ⊢ 𝑆 = (StarGr‘𝑁)
6		isubgr3stgr.w	. . 3 ⊢ 𝑊 = (Vtx‘𝑆)
7	1, 2, 3, 4, 5, 6	isubgr3stgrlem2 47869	. 2 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → ∃𝑓 𝑓:𝑈–1-1-onto→(𝑊 ∖ {0}))
8		f1odm 6852	. . . 4 ⊢ (𝑓:𝑈–1-1-onto→(𝑊 ∖ {0}) → dom 𝑓 = 𝑈)
9		simpr 484	. . . . . . 7 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ 𝑓:𝑈–1-1-onto→(𝑊 ∖ {0})) → 𝑓:𝑈–1-1-onto→(𝑊 ∖ {0}))
10		simpl2 1191	. . . . . . 7 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ 𝑓:𝑈–1-1-onto→(𝑊 ∖ {0})) → 𝑋 ∈ 𝑉)
11		c0ex 11252	. . . . . . . 8 ⊢ 0 ∈ V
12	11	a1i 11	. . . . . . 7 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ 𝑓:𝑈–1-1-onto→(𝑊 ∖ {0})) → 0 ∈ V)
13		neldifsnd 4797	. . . . . . . 8 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ 𝑓:𝑈–1-1-onto→(𝑊 ∖ {0})) → ¬ 0 ∈ (𝑊 ∖ {0}))
14		df-nel 3044	. . . . . . . 8 ⊢ (0 ∉ (𝑊 ∖ {0}) ↔ ¬ 0 ∈ (𝑊 ∖ {0}))
15	13, 14	sylibr 234	. . . . . . 7 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ 𝑓:𝑈–1-1-onto→(𝑊 ∖ {0})) → 0 ∉ (𝑊 ∖ {0}))
16		eqid 2734	. . . . . . . 8 ⊢ (𝑓 ∪ {⟨𝑋, 0⟩}) = (𝑓 ∪ {⟨𝑋, 0⟩})
17	1, 2, 3, 16	isubgr3stgrlem1 47868	. . . . . . 7 ⊢ ((𝑓:𝑈–1-1-onto→(𝑊 ∖ {0}) ∧ 𝑋 ∈ 𝑉 ∧ (0 ∈ V ∧ 0 ∉ (𝑊 ∖ {0}))) → (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}))
18	9, 10, 12, 15, 17	syl112anc 1373	. . . . . 6 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ 𝑓:𝑈–1-1-onto→(𝑊 ∖ {0})) → (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}))
19	18	ex 412	. . . . 5 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → (𝑓:𝑈–1-1-onto→(𝑊 ∖ {0}) → (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0})))
20		f1of 6848	. . . . . . . . 9 ⊢ ((𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) → (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶⟶((𝑊 ∖ {0}) ∪ {0}))
21	20	3ad2ant2 1133	. . . . . . . 8 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶⟶((𝑊 ∖ {0}) ∪ {0}))
22	3	ovexi 7464	. . . . . . . . 9 ⊢ 𝐶 ∈ V
23	22	a1i 11	. . . . . . . 8 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → 𝐶 ∈ V)
24	21, 23	fexd 7246	. . . . . . 7 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → (𝑓 ∪ {⟨𝑋, 0⟩}) ∈ V)
25	5, 6	stgrvtx0 47864	. . . . . . . . . . . . . 14 ⊢ (𝑁 ∈ ℕ0 → 0 ∈ 𝑊)
26	4, 25	mp1i 13	. . . . . . . . . . . . 13 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → 0 ∈ 𝑊)
27	26	snssd 4813	. . . . . . . . . . . 12 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → {0} ⊆ 𝑊)
28		undifr 4488	. . . . . . . . . . . 12 ⊢ ({0} ⊆ 𝑊 ↔ ((𝑊 ∖ {0}) ∪ {0}) = 𝑊)
29	27, 28	sylib 218	. . . . . . . . . . 11 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → ((𝑊 ∖ {0}) ∪ {0}) = 𝑊)
30	29	f1oeq3d 6845	. . . . . . . . . 10 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → ((𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ↔ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→𝑊))
31	30	biimpa 476	. . . . . . . . 9 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0})) → (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→𝑊)
32	31	3adant3 1131	. . . . . . . 8 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→𝑊)
33		simp12 1203	. . . . . . . . 9 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → 𝑋 ∈ 𝑉)
34	11	a1i 11	. . . . . . . . 9 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → 0 ∈ V)
35		nbgrnself2 29391	. . . . . . . . . . 11 ⊢ 𝑋 ∉ (𝐺 NeighbVtx 𝑋)
36		df-nel 3044	. . . . . . . . . . . 12 ⊢ (𝑋 ∉ (𝐺 NeighbVtx 𝑋) ↔ ¬ 𝑋 ∈ (𝐺 NeighbVtx 𝑋))
37	2	eleq2i 2830	. . . . . . . . . . . 12 ⊢ (𝑋 ∈ 𝑈 ↔ 𝑋 ∈ (𝐺 NeighbVtx 𝑋))
38	36, 37	xchbinxr 335	. . . . . . . . . . 11 ⊢ (𝑋 ∉ (𝐺 NeighbVtx 𝑋) ↔ ¬ 𝑋 ∈ 𝑈)
39	35, 38	mpbi 230	. . . . . . . . . 10 ⊢ ¬ 𝑋 ∈ 𝑈
40		eleq2 2827	. . . . . . . . . . . 12 ⊢ (dom 𝑓 = 𝑈 → (𝑋 ∈ dom 𝑓 ↔ 𝑋 ∈ 𝑈))
41	40	notbid 318	. . . . . . . . . . 11 ⊢ (dom 𝑓 = 𝑈 → (¬ 𝑋 ∈ dom 𝑓 ↔ ¬ 𝑋 ∈ 𝑈))
42	41	3ad2ant3 1134	. . . . . . . . . 10 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → (¬ 𝑋 ∈ dom 𝑓 ↔ ¬ 𝑋 ∈ 𝑈))
43	39, 42	mpbiri 258	. . . . . . . . 9 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → ¬ 𝑋 ∈ dom 𝑓)
44		fsnunfv 7206	. . . . . . . . 9 ⊢ ((𝑋 ∈ 𝑉 ∧ 0 ∈ V ∧ ¬ 𝑋 ∈ dom 𝑓) → ((𝑓 ∪ {⟨𝑋, 0⟩})‘𝑋) = 0)
45	33, 34, 43, 44	syl3anc 1370	. . . . . . . 8 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → ((𝑓 ∪ {⟨𝑋, 0⟩})‘𝑋) = 0)
46	32, 45	jca 511	. . . . . . 7 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → ((𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→𝑊 ∧ ((𝑓 ∪ {⟨𝑋, 0⟩})‘𝑋) = 0))
47		f1oeq1 6836	. . . . . . . 8 ⊢ (𝑔 = (𝑓 ∪ {⟨𝑋, 0⟩}) → (𝑔:𝐶–1-1-onto→𝑊 ↔ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→𝑊))
48		fveq1 6905	. . . . . . . . 9 ⊢ (𝑔 = (𝑓 ∪ {⟨𝑋, 0⟩}) → (𝑔‘𝑋) = ((𝑓 ∪ {⟨𝑋, 0⟩})‘𝑋))
49	48	eqeq1d 2736	. . . . . . . 8 ⊢ (𝑔 = (𝑓 ∪ {⟨𝑋, 0⟩}) → ((𝑔‘𝑋) = 0 ↔ ((𝑓 ∪ {⟨𝑋, 0⟩})‘𝑋) = 0))
50	47, 49	anbi12d 632	. . . . . . 7 ⊢ (𝑔 = (𝑓 ∪ {⟨𝑋, 0⟩}) → ((𝑔:𝐶–1-1-onto→𝑊 ∧ (𝑔‘𝑋) = 0) ↔ ((𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→𝑊 ∧ ((𝑓 ∪ {⟨𝑋, 0⟩})‘𝑋) = 0)))
51	24, 46, 50	spcedv 3597	. . . . . 6 ⊢ (((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) ∧ (𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) ∧ dom 𝑓 = 𝑈) → ∃𝑔(𝑔:𝐶–1-1-onto→𝑊 ∧ (𝑔‘𝑋) = 0))
52	51	3exp 1118	. . . . 5 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → ((𝑓 ∪ {⟨𝑋, 0⟩}):𝐶–1-1-onto→((𝑊 ∖ {0}) ∪ {0}) → (dom 𝑓 = 𝑈 → ∃𝑔(𝑔:𝐶–1-1-onto→𝑊 ∧ (𝑔‘𝑋) = 0))))
53	19, 52	syld 47	. . . 4 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → (𝑓:𝑈–1-1-onto→(𝑊 ∖ {0}) → (dom 𝑓 = 𝑈 → ∃𝑔(𝑔:𝐶–1-1-onto→𝑊 ∧ (𝑔‘𝑋) = 0))))
54	8, 53	mpdi 45	. . 3 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → (𝑓:𝑈–1-1-onto→(𝑊 ∖ {0}) → ∃𝑔(𝑔:𝐶–1-1-onto→𝑊 ∧ (𝑔‘𝑋) = 0)))
55	54	exlimdv 1930	. 2 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → (∃𝑓 𝑓:𝑈–1-1-onto→(𝑊 ∖ {0}) → ∃𝑔(𝑔:𝐶–1-1-onto→𝑊 ∧ (𝑔‘𝑋) = 0)))
56	7, 55	mpd 15	1 ⊢ ((𝐺 ∈ USGraph ∧ 𝑋 ∈ 𝑉 ∧ (♯‘𝑈) = 𝑁) → ∃𝑔(𝑔:𝐶–1-1-onto→𝑊 ∧ (𝑔‘𝑋) = 0))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 206   ∧ wa 395   ∧ w3a 1086   = wceq 1536  ∃wex 1775   ∈ wcel 2105   ∉ wnel 3043  Vcvv 3477   ∖ cdif 3959   ∪ cun 3960   ⊆ wss 3962  {csn 4630  ⟨cop 4636  dom cdm 5688  ⟶wf 6558  –1-1-onto→wf1o 6561  ‘cfv 6562  (class class class)co 7430  0cc0 11152  ℕ₀cn0 12523  ♯chash 14365  Vtxcvtx 29027  USGraphcusgr 29180   NeighbVtx cnbgr 29363   ClNeighbVtx cclnbgr 47742  StarGrcstgr 47853

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1791  ax-4 1805  ax-5 1907  ax-6 1964  ax-7 2004  ax-8 2107  ax-9 2115  ax-10 2138  ax-11 2154  ax-12 2174  ax-ext 2705  ax-rep 5284  ax-sep 5301  ax-nul 5311  ax-pow 5370  ax-pr 5437  ax-un 7753  ax-cnex 11208  ax-resscn 11209  ax-1cn 11210  ax-icn 11211  ax-addcl 11212  ax-addrcl 11213  ax-mulcl 11214  ax-mulrcl 11215  ax-mulcom 11216  ax-addass 11217  ax-mulass 11218  ax-distr 11219  ax-i2m1 11220  ax-1ne0 11221  ax-1rid 11222  ax-rnegex 11223  ax-rrecex 11224  ax-cnre 11225  ax-pre-lttri 11226  ax-pre-lttrn 11227  ax-pre-ltadd 11228  ax-pre-mulgt0 11229

This theorem depends on definitions:  df-bi 207  df-an 396  df-or 848  df-3or 1087  df-3an 1088  df-tru 1539  df-fal 1549  df-ex 1776  df-nf 1780  df-sb 2062  df-mo 2537  df-eu 2566  df-clab 2712  df-cleq 2726  df-clel 2813  df-nfc 2889  df-ne 2938  df-nel 3044  df-ral 3059  df-rex 3068  df-reu 3378  df-rab 3433  df-v 3479  df-sbc 3791  df-csb 3908  df-dif 3965  df-un 3967  df-in 3969  df-ss 3979  df-pss 3982  df-nul 4339  df-if 4531  df-pw 4606  df-sn 4631  df-pr 4633  df-op 4637  df-uni 4912  df-int 4951  df-iun 4997  df-br 5148  df-opab 5210  df-mpt 5231  df-tr 5265  df-id 5582  df-eprel 5588  df-po 5596  df-so 5597  df-fr 5640  df-we 5642  df-xp 5694  df-rel 5695  df-cnv 5696  df-co 5697  df-dm 5698  df-rn 5699  df-res 5700  df-ima 5701  df-pred 6322  df-ord 6388  df-on 6389  df-lim 6390  df-suc 6391  df-iota 6515  df-fun 6564  df-fn 6565  df-f 6566  df-f1 6567  df-fo 6568  df-f1o 6569  df-fv 6570  df-riota 7387  df-ov 7433  df-oprab 7434  df-mpo 7435  df-om 7887  df-1st 8012  df-2nd 8013  df-frecs 8304  df-wrecs 8335  df-recs 8409  df-rdg 8448  df-1o 8504  df-oadd 8508  df-er 8743  df-en 8984  df-dom 8985  df-sdom 8986  df-fin 8987  df-dju 9938  df-card 9976  df-pnf 11294  df-mnf 11295  df-xr 11296  df-ltxr 11297  df-le 11298  df-sub 11491  df-neg 11492  df-nn 12264  df-2 12326  df-3 12327  df-4 12328  df-5 12329  df-6 12330  df-7 12331  df-8 12332  df-9 12333  df-n0 12524  df-xnn0 12597  df-z 12611  df-dec 12731  df-uz 12876  df-fz 13544  df-hash 14366  df-struct 17180  df-slot 17215  df-ndx 17227  df-base 17245  df-edgf 29018  df-vtx 29029  df-nbgr 29364  df-clnbgr 47743  df-stgr 47854

This theorem is referenced by:  isubgr3stgr  47877