Theorem elwspths2on 28370

Description: A simple path of length 2 between two vertices (in a graph) as length 3 string. (Contributed by Alexander van der Vekens, 9-Mar-2018.) (Revised by AV, 12-May-2021.) (Proof shortened by AV, 16-Mar-2022.)

Hypothesis

Ref	Expression
elwwlks2on.v	⊢ 𝑉 = (Vtx‘𝐺)

Assertion

Ref	Expression
elwspths2on	⊢ ((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) ↔ ∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))))

Distinct variable groups:   𝐴,𝑏   𝐶,𝑏   𝐺,𝑏   𝑉,𝑏   𝑊,𝑏

Proof of Theorem elwspths2on

Dummy variable 𝑓 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		wspthnon 28268	. . . 4 ⊢ (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) ↔ (𝑊 ∈ (𝐴(2 WWalksNOn 𝐺)𝐶) ∧ ∃𝑓 𝑓(𝐴(SPathsOn‘𝐺)𝐶)𝑊))
2	1	biimpi 215	. . 3 ⊢ (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → (𝑊 ∈ (𝐴(2 WWalksNOn 𝐺)𝐶) ∧ ∃𝑓 𝑓(𝐴(SPathsOn‘𝐺)𝐶)𝑊))
3		elwwlks2on.v	. . . . . . 7 ⊢ 𝑉 = (Vtx‘𝐺)
4	3	elwwlks2on 28369	. . . . . 6 ⊢ ((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → (𝑊 ∈ (𝐴(2 WWalksNOn 𝐺)𝐶) ↔ ∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ∃𝑓(𝑓(Walks‘𝐺)𝑊 ∧ (♯‘𝑓) = 2))))
5		simpl 484	. . . . . . . . . . . . 13 ⊢ ((𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ 𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)) → 𝑊 = ⟨“𝐴𝑏𝐶”⟩)
6		eleq1 2824	. . . . . . . . . . . . . 14 ⊢ (𝑊 = ⟨“𝐴𝑏𝐶”⟩ → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) ↔ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)))
7	6	biimpa 478	. . . . . . . . . . . . 13 ⊢ ((𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ 𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)) → ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))
8	5, 7	jca 513	. . . . . . . . . . . 12 ⊢ ((𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ 𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)) → (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)))
9	8	ex 414	. . . . . . . . . . 11 ⊢ (𝑊 = ⟨“𝐴𝑏𝐶”⟩ → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))))
10	9	adantr 482	. . . . . . . . . 10 ⊢ ((𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ∃𝑓(𝑓(Walks‘𝐺)𝑊 ∧ (♯‘𝑓) = 2)) → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))))
11	10	com12 32	. . . . . . . . 9 ⊢ (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → ((𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ∃𝑓(𝑓(Walks‘𝐺)𝑊 ∧ (♯‘𝑓) = 2)) → (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))))
12	11	reximdv 3164	. . . . . . . 8 ⊢ (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → (∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ∃𝑓(𝑓(Walks‘𝐺)𝑊 ∧ (♯‘𝑓) = 2)) → ∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))))
13	12	a1i13 27	. . . . . . 7 ⊢ ((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → (∃𝑓 𝑓(𝐴(SPathsOn‘𝐺)𝐶)𝑊 → (∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ∃𝑓(𝑓(Walks‘𝐺)𝑊 ∧ (♯‘𝑓) = 2)) → ∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))))))
14	13	com24 95	. . . . . 6 ⊢ ((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → (∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ∃𝑓(𝑓(Walks‘𝐺)𝑊 ∧ (♯‘𝑓) = 2)) → (∃𝑓 𝑓(𝐴(SPathsOn‘𝐺)𝐶)𝑊 → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → ∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))))))
15	4, 14	sylbid 239	. . . . 5 ⊢ ((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → (𝑊 ∈ (𝐴(2 WWalksNOn 𝐺)𝐶) → (∃𝑓 𝑓(𝐴(SPathsOn‘𝐺)𝐶)𝑊 → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → ∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))))))
16	15	impd 412	. . . 4 ⊢ ((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → ((𝑊 ∈ (𝐴(2 WWalksNOn 𝐺)𝐶) ∧ ∃𝑓 𝑓(𝐴(SPathsOn‘𝐺)𝐶)𝑊) → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → ∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)))))
17	16	com23 86	. . 3 ⊢ ((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → ((𝑊 ∈ (𝐴(2 WWalksNOn 𝐺)𝐶) ∧ ∃𝑓 𝑓(𝐴(SPathsOn‘𝐺)𝐶)𝑊) → ∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)))))
18	2, 17	mpdi 45	. 2 ⊢ ((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) → ∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))))
19	6	biimpar 479	. . . 4 ⊢ ((𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)) → 𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))
20	19	a1i 11	. . 3 ⊢ (((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) ∧ 𝑏 ∈ 𝑉) → ((𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)) → 𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)))
21	20	rexlimdva 3149	. 2 ⊢ ((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → (∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)) → 𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶)))
22	18, 21	impbid 211	1 ⊢ ((𝐺 ∈ UPGraph ∧ 𝐴 ∈ 𝑉 ∧ 𝐶 ∈ 𝑉) → (𝑊 ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶) ↔ ∃𝑏 ∈ 𝑉 (𝑊 = ⟨“𝐴𝑏𝐶”⟩ ∧ ⟨“𝐴𝑏𝐶”⟩ ∈ (𝐴(2 WSPathsNOn 𝐺)𝐶))))

Syntax hints:   → wi 4   ↔ wb 205   ∧ wa 397   ∧ w3a 1087   = wceq 1539  ∃wex 1779   ∈ wcel 2104  ∃wrex 3071   class class class wbr 5081  ‘cfv 6458  (class class class)co 7307  2c2 12074  ♯chash 14090  ⟨“cs3 14600  Vtxcvtx 27411  UPGraphcupgr 27495  Walkscwlks 28008  SPathsOncspthson 28128   WWalksNOn cwwlksnon 28237   WSPathsNOn cwwspthsnon 28239

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1911  ax-6 1969  ax-7 2009  ax-8 2106  ax-9 2114  ax-10 2135  ax-11 2152  ax-12 2169  ax-ext 2707  ax-rep 5218  ax-sep 5232  ax-nul 5239  ax-pow 5297  ax-pr 5361  ax-un 7620  ax-ac2 10265  ax-cnex 10973  ax-resscn 10974  ax-1cn 10975  ax-icn 10976  ax-addcl 10977  ax-addrcl 10978  ax-mulcl 10979  ax-mulrcl 10980  ax-mulcom 10981  ax-addass 10982  ax-mulass 10983  ax-distr 10984  ax-i2m1 10985  ax-1ne0 10986  ax-1rid 10987  ax-rnegex 10988  ax-rrecex 10989  ax-cnre 10990  ax-pre-lttri 10991  ax-pre-lttrn 10992  ax-pre-ltadd 10993  ax-pre-mulgt0 10994

This theorem depends on definitions:  df-bi 206  df-an 398  df-or 846  df-ifp 1062  df-3or 1088  df-3an 1089  df-tru 1542  df-fal 1552  df-ex 1780  df-nf 1784  df-sb 2066  df-mo 2538  df-eu 2567  df-clab 2714  df-cleq 2728  df-clel 2814  df-nfc 2887  df-ne 2942  df-nel 3048  df-ral 3063  df-rex 3072  df-rmo 3285  df-reu 3286  df-rab 3287  df-v 3439  df-sbc 3722  df-csb 3838  df-dif 3895  df-un 3897  df-in 3899  df-ss 3909  df-pss 3911  df-nul 4263  df-if 4466  df-pw 4541  df-sn 4566  df-pr 4568  df-tp 4570  df-op 4572  df-uni 4845  df-int 4887  df-iun 4933  df-br 5082  df-opab 5144  df-mpt 5165  df-tr 5199  df-id 5500  df-eprel 5506  df-po 5514  df-so 5515  df-fr 5555  df-se 5556  df-we 5557  df-xp 5606  df-rel 5607  df-cnv 5608  df-co 5609  df-dm 5610  df-rn 5611  df-res 5612  df-ima 5613  df-pred 6217  df-ord 6284  df-on 6285  df-lim 6286  df-suc 6287  df-iota 6410  df-fun 6460  df-fn 6461  df-f 6462  df-f1 6463  df-fo 6464  df-f1o 6465  df-fv 6466  df-isom 6467  df-riota 7264  df-ov 7310  df-oprab 7311  df-mpo 7312  df-om 7745  df-1st 7863  df-2nd 7864  df-frecs 8128  df-wrecs 8159  df-recs 8233  df-rdg 8272  df-1o 8328  df-2o 8329  df-oadd 8332  df-er 8529  df-map 8648  df-pm 8649  df-en 8765  df-dom 8766  df-sdom 8767  df-fin 8768  df-dju 9703  df-card 9741  df-ac 9918  df-pnf 11057  df-mnf 11058  df-xr 11059  df-ltxr 11060  df-le 11061  df-sub 11253  df-neg 11254  df-nn 12020  df-2 12082  df-3 12083  df-n0 12280  df-xnn0 12352  df-z 12366  df-uz 12629  df-fz 13286  df-fzo 13429  df-hash 14091  df-word 14263  df-concat 14319  df-s1 14346  df-s2 14606  df-s3 14607  df-edg 27463  df-uhgr 27473  df-upgr 27497  df-wlks 28011  df-wwlks 28240  df-wwlksn 28241  df-wwlksnon 28242  df-wspthsnon 28244

This theorem is referenced by:  usgr2wspthon  28375  elwspths2spth  28377