clwwlknclwwlkdifnum - Metamath Proof Explorer

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Theorem clwwlknclwwlkdifnum 26946

Description: In a 𝐾-regular graph, the size of the set 𝐴 of walks of length 𝑁 starting with a fixed vertex 𝑋 and ending not at this vertex is the difference between 𝐾 to the power of 𝑁 and the size of the set 𝐵 of closed walks of length 𝑁 anchored at this vertex 𝑋. (Contributed by Alexander van der Vekens, 30-Sep-2018.) (Revised by AV, 7-May-2021.) (Revised by AV, 8-Mar-2022.) (Proof shortened by AV, 16-Mar-2022.)

**Hypotheses**
Ref	Expression
clwwlknclwwlkdif.a	⊢ 𝐴 = {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ ((𝑤‘0) = 𝑋 ∧ ( lastS ‘𝑤) ≠ 𝑋)}
clwwlknclwwlkdif.b	⊢ 𝐵 = (𝑋(𝑁 WWalksNOn 𝐺)𝑋)
clwwlknclwwlkdifnum.v	⊢ 𝑉 = (Vtx‘𝐺)

**Assertion**
Ref	Expression
clwwlknclwwlkdifnum	⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → (#‘𝐴) = ((𝐾↑𝑁) − (#‘𝐵)))

Distinct variable groups: 𝑤,𝐺 𝑤,𝑁 𝑤,𝑋 𝑤,𝐾 𝑤,𝑉 Allowed substitution hints: 𝐴(𝑤) 𝐵(𝑤)

**Proof of Theorem clwwlknclwwlkdifnum**
Step	Hyp	Ref	Expression
1		clwwlknclwwlkdif.a	. . . . 5 ⊢ 𝐴 = {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ ((𝑤‘0) = 𝑋 ∧ ( lastS ‘𝑤) ≠ 𝑋)}
2		clwwlknclwwlkdif.b	. . . . 5 ⊢ 𝐵 = (𝑋(𝑁 WWalksNOn 𝐺)𝑋)
3		eqid 2651	. . . . 5 ⊢ {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋} = {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋}
4	1, 2, 3	clwwlknclwwlkdif 26945	. . . 4 ⊢ 𝐴 = ({𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋} ∖ 𝐵)
5	4	fveq2i 6232	. . 3 ⊢ (#‘𝐴) = (#‘({𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋} ∖ 𝐵))
6	5	a1i 11	. 2 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → (#‘𝐴) = (#‘({𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋} ∖ 𝐵)))
7		clwwlknclwwlkdifnum.v	. . . . . . . 8 ⊢ 𝑉 = (Vtx‘𝐺)
8	7	eleq1i 2721	. . . . . . 7 ⊢ (𝑉 ∈ Fin ↔ (Vtx‘𝐺) ∈ Fin)
9	8	biimpi 206	. . . . . 6 ⊢ (𝑉 ∈ Fin → (Vtx‘𝐺) ∈ Fin)
10	9	adantl 481	. . . . 5 ⊢ ((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) → (Vtx‘𝐺) ∈ Fin)
11	10	adantr 480	. . . 4 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → (Vtx‘𝐺) ∈ Fin)
12		wwlksnfi 26869	. . . 4 ⊢ ((Vtx‘𝐺) ∈ Fin → (𝑁 WWalksN 𝐺) ∈ Fin)
13		rabfi 8226	. . . 4 ⊢ ((𝑁 WWalksN 𝐺) ∈ Fin → {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋} ∈ Fin)
14	11, 12, 13	3syl 18	. . 3 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋} ∈ Fin)
15	7	iswwlksnon 26802	. . . . . . . 8 ⊢ (𝑋(𝑁 WWalksNOn 𝐺)𝑋) = {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ ((𝑤‘0) = 𝑋 ∧ (𝑤‘𝑁) = 𝑋)}
16		ancom 465	. . . . . . . . 9 ⊢ (((𝑤‘0) = 𝑋 ∧ (𝑤‘𝑁) = 𝑋) ↔ ((𝑤‘𝑁) = 𝑋 ∧ (𝑤‘0) = 𝑋))
17	16	rabbii 3216	. . . . . . . 8 ⊢ {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ ((𝑤‘0) = 𝑋 ∧ (𝑤‘𝑁) = 𝑋)} = {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ ((𝑤‘𝑁) = 𝑋 ∧ (𝑤‘0) = 𝑋)}
18	15, 17	eqtri 2673	. . . . . . 7 ⊢ (𝑋(𝑁 WWalksNOn 𝐺)𝑋) = {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ ((𝑤‘𝑁) = 𝑋 ∧ (𝑤‘0) = 𝑋)}
19	18	a1i 11	. . . . . 6 ⊢ ((𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀) → (𝑋(𝑁 WWalksNOn 𝐺)𝑋) = {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ ((𝑤‘𝑁) = 𝑋 ∧ (𝑤‘0) = 𝑋)})
20	2, 19	syl5eq 2697	. . . . 5 ⊢ ((𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀) → 𝐵 = {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ ((𝑤‘𝑁) = 𝑋 ∧ (𝑤‘0) = 𝑋)})
21		simpr 476	. . . . . . 7 ⊢ (((𝑤‘𝑁) = 𝑋 ∧ (𝑤‘0) = 𝑋) → (𝑤‘0) = 𝑋)
22	21	a1i 11	. . . . . 6 ⊢ (𝑤 ∈ (𝑁 WWalksN 𝐺) → (((𝑤‘𝑁) = 𝑋 ∧ (𝑤‘0) = 𝑋) → (𝑤‘0) = 𝑋))
23	22	ss2rabi 3717	. . . . 5 ⊢ {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ ((𝑤‘𝑁) = 𝑋 ∧ (𝑤‘0) = 𝑋)} ⊆ {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋}
24	20, 23	syl6eqss 3688	. . . 4 ⊢ ((𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀) → 𝐵 ⊆ {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋})
25	24	adantl 481	. . 3 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → 𝐵 ⊆ {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋})
26		hashssdif 13238	. . 3 ⊢ (({𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋} ∈ Fin ∧ 𝐵 ⊆ {𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋}) → (#‘({𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋} ∖ 𝐵)) = ((#‘{𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋}) − (#‘𝐵)))
27	14, 25, 26	syl2anc 694	. 2 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → (#‘({𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋} ∖ 𝐵)) = ((#‘{𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋}) − (#‘𝐵)))
28		simpl 472	. . . . 5 ⊢ ((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) → 𝐺RegUSGraph𝐾)
29	28	adantr 480	. . . 4 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → 𝐺RegUSGraph𝐾)
30		simpr 476	. . . . 5 ⊢ ((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) → 𝑉 ∈ Fin)
31	30	adantr 480	. . . 4 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → 𝑉 ∈ Fin)
32		simpl 472	. . . . 5 ⊢ ((𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀) → 𝑋 ∈ 𝑉)
33	32	adantl 481	. . . 4 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → 𝑋 ∈ 𝑉)
34		simpr 476	. . . . 5 ⊢ ((𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀) → 𝑁 ∈ ℕ₀)
35	34	adantl 481	. . . 4 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → 𝑁 ∈ ℕ₀)
36	7	rusgrnumwwlkg 26943	. . . 4 ⊢ ((𝐺RegUSGraph𝐾 ∧ (𝑉 ∈ Fin ∧ 𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → (#‘{𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋}) = (𝐾↑𝑁))
37	29, 31, 33, 35, 36	syl13anc 1368	. . 3 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → (#‘{𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋}) = (𝐾↑𝑁))
38	37	oveq1d 6705	. 2 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → ((#‘{𝑤 ∈ (𝑁 WWalksN 𝐺) ∣ (𝑤‘0) = 𝑋}) − (#‘𝐵)) = ((𝐾↑𝑁) − (#‘𝐵)))
39	6, 27, 38	3eqtrd 2689	1 ⊢ (((𝐺RegUSGraph𝐾 ∧ 𝑉 ∈ Fin) ∧ (𝑋 ∈ 𝑉 ∧ 𝑁 ∈ ℕ₀)) → (#‘𝐴) = ((𝐾↑𝑁) − (#‘𝐵)))

Colors of variables: wff setvar class

Syntax hints: → wi 4 ∧ wa 383 = wceq 1523 ∈ wcel 2030 ≠ wne 2823 {crab 2945 ∖ cdif 3604 ⊆ wss 3607 class class class wbr 4685 ‘cfv 5926 (class class class)co 6690 Fincfn 7997 0cc0 9974 − cmin 10304 ℕ₀cn0 11330 ↑cexp 12900 #chash 13157 lastS clsw 13324 Vtxcvtx 25919 RegUSGraphcrusgr 26508 WWalksN cwwlksn 26774 WWalksNOn cwwlksnon 26775

This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1762 ax-4 1777 ax-5 1879 ax-6 1945 ax-7 1981 ax-8 2032 ax-9 2039 ax-10 2059 ax-11 2074 ax-12 2087 ax-13 2282 ax-ext 2631 ax-rep 4804 ax-sep 4814 ax-nul 4822 ax-pow 4873 ax-pr 4936 ax-un 6991 ax-inf2 8576 ax-cnex 10030 ax-resscn 10031 ax-1cn 10032 ax-icn 10033 ax-addcl 10034 ax-addrcl 10035 ax-mulcl 10036 ax-mulrcl 10037 ax-mulcom 10038 ax-addass 10039 ax-mulass 10040 ax-distr 10041 ax-i2m1 10042 ax-1ne0 10043 ax-1rid 10044 ax-rnegex 10045 ax-rrecex 10046 ax-cnre 10047 ax-pre-lttri 10048 ax-pre-lttrn 10049 ax-pre-ltadd 10050 ax-pre-mulgt0 10051 ax-pre-sup 10052

This theorem depends on definitions: df-bi 197 df-or 384 df-an 385 df-3or 1055 df-3an 1056 df-tru 1526 df-fal 1529 df-ex 1745 df-nf 1750 df-sb 1938 df-eu 2502 df-mo 2503 df-clab 2638 df-cleq 2644 df-clel 2647 df-nfc 2782 df-ne 2824 df-nel 2927 df-ral 2946 df-rex 2947 df-reu 2948 df-rmo 2949 df-rab 2950 df-v 3233 df-sbc 3469 df-csb 3567 df-dif 3610 df-un 3612 df-in 3614 df-ss 3621 df-pss 3623 df-nul 3949 df-if 4120 df-pw 4193 df-sn 4211 df-pr 4213 df-tp 4215 df-op 4217 df-uni 4469 df-int 4508 df-iun 4554 df-disj 4653 df-br 4686 df-opab 4746 df-mpt 4763 df-tr 4786 df-id 5053 df-eprel 5058 df-po 5064 df-so 5065 df-fr 5102 df-se 5103 df-we 5104 df-xp 5149 df-rel 5150 df-cnv 5151 df-co 5152 df-dm 5153 df-rn 5154 df-res 5155 df-ima 5156 df-pred 5718 df-ord 5764 df-on 5765 df-lim 5766 df-suc 5767 df-iota 5889 df-fun 5928 df-fn 5929 df-f 5930 df-f1 5931 df-fo 5932 df-f1o 5933 df-fv 5934 df-isom 5935 df-riota 6651 df-ov 6693 df-oprab 6694 df-mpt2 6695 df-om 7108 df-1st 7210 df-2nd 7211 df-wrecs 7452 df-recs 7513 df-rdg 7551 df-1o 7605 df-2o 7606 df-oadd 7609 df-er 7787 df-map 7901 df-pm 7902 df-en 7998 df-dom 7999 df-sdom 8000 df-fin 8001 df-sup 8389 df-oi 8456 df-card 8803 df-cda 9028 df-pnf 10114 df-mnf 10115 df-xr 10116 df-ltxr 10117 df-le 10118 df-sub 10306 df-neg 10307 df-div 10723 df-nn 11059 df-2 11117 df-3 11118 df-n0 11331 df-xnn0 11402 df-z 11416 df-uz 11726 df-rp 11871 df-xadd 11985 df-fz 12365 df-fzo 12505 df-seq 12842 df-exp 12901 df-hash 13158 df-word 13331 df-lsw 13332 df-concat 13333 df-s1 13334 df-substr 13335 df-cj 13883 df-re 13884 df-im 13885 df-sqrt 14019 df-abs 14020 df-clim 14263 df-sum 14461 df-vtx 25921 df-iedg 25922 df-edg 25985 df-uhgr 25998 df-ushgr 25999 df-upgr 26022 df-umgr 26023 df-uspgr 26090 df-usgr 26091 df-fusgr 26254 df-nbgr 26270 df-vtxdg 26418 df-rgr 26509 df-rusgr 26510 df-wwlks 26778 df-wwlksn 26779 df-wwlksnon 26780

This theorem is referenced by: numclwwlkqhash 27355

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