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Theorem swrdccat3b 11267
Description: A suffix of a concatenation is either a suffix of the second concatenated word or a concatenation of a suffix of the first word with the second word. (Contributed by Alexander van der Vekens, 31-Mar-2018.) (Revised by Alexander van der Vekens, 30-May-2018.) (Proof shortened by AV, 14-Oct-2022.)
Hypothesis
Ref Expression
swrdccatin2.l 𝐿 = (♯‘𝐴)
Assertion
Ref Expression
swrdccat3b ((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) → (𝑀 ∈ (0...(𝐿 + (♯‘𝐵))) → ((𝐴 ++ 𝐵) substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩) = if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵))))

Proof of Theorem swrdccat3b
StepHypRef Expression
1 simpl 109 . . . 4 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → (𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉))
2 simpr 110 . . . 4 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → 𝑀 ∈ (0...(𝐿 + (♯‘𝐵))))
3 elfzubelfz 10228 . . . . 5 (𝑀 ∈ (0...(𝐿 + (♯‘𝐵))) → (𝐿 + (♯‘𝐵)) ∈ (0...(𝐿 + (♯‘𝐵))))
43adantl 277 . . . 4 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → (𝐿 + (♯‘𝐵)) ∈ (0...(𝐿 + (♯‘𝐵))))
5 swrdccatin2.l . . . . . 6 𝐿 = (♯‘𝐴)
65pfxccat3 11261 . . . . 5 ((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) → ((𝑀 ∈ (0...(𝐿 + (♯‘𝐵))) ∧ (𝐿 + (♯‘𝐵)) ∈ (0...(𝐿 + (♯‘𝐵)))) → ((𝐴 ++ 𝐵) substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩) = if((𝐿 + (♯‘𝐵)) ≤ 𝐿, (𝐴 substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩), if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), ((𝐿 + (♯‘𝐵)) − 𝐿)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ (𝐵 prefix ((𝐿 + (♯‘𝐵)) − 𝐿)))))))
76imp 124 . . . 4 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ (𝑀 ∈ (0...(𝐿 + (♯‘𝐵))) ∧ (𝐿 + (♯‘𝐵)) ∈ (0...(𝐿 + (♯‘𝐵))))) → ((𝐴 ++ 𝐵) substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩) = if((𝐿 + (♯‘𝐵)) ≤ 𝐿, (𝐴 substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩), if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), ((𝐿 + (♯‘𝐵)) − 𝐿)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ (𝐵 prefix ((𝐿 + (♯‘𝐵)) − 𝐿))))))
81, 2, 4, 7syl12anc 1269 . . 3 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → ((𝐴 ++ 𝐵) substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩) = if((𝐿 + (♯‘𝐵)) ≤ 𝐿, (𝐴 substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩), if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), ((𝐿 + (♯‘𝐵)) − 𝐿)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ (𝐵 prefix ((𝐿 + (♯‘𝐵)) − 𝐿))))))
95swrdccat3blem 11266 . . . 4 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ (𝐿 + (♯‘𝐵)) ≤ 𝐿) → if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)) = (𝐴 substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩))
10 iftrue 3607 . . . . . 6 (𝐿𝑀 → if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)) = (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩))
11103ad2ant3 1044 . . . . 5 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿𝐿𝑀) → if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)) = (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩))
12 lencl 11070 . . . . . . . . . . . 12 (𝐴 ∈ Word 𝑉 → (♯‘𝐴) ∈ ℕ0)
1312nn0cnd 9420 . . . . . . . . . . 11 (𝐴 ∈ Word 𝑉 → (♯‘𝐴) ∈ ℂ)
14 lencl 11070 . . . . . . . . . . . 12 (𝐵 ∈ Word 𝑉 → (♯‘𝐵) ∈ ℕ0)
1514nn0cnd 9420 . . . . . . . . . . 11 (𝐵 ∈ Word 𝑉 → (♯‘𝐵) ∈ ℂ)
165eqcomi 2233 . . . . . . . . . . . . 13 (♯‘𝐴) = 𝐿
1716eleq1i 2295 . . . . . . . . . . . 12 ((♯‘𝐴) ∈ ℂ ↔ 𝐿 ∈ ℂ)
18 pncan2 8349 . . . . . . . . . . . 12 ((𝐿 ∈ ℂ ∧ (♯‘𝐵) ∈ ℂ) → ((𝐿 + (♯‘𝐵)) − 𝐿) = (♯‘𝐵))
1917, 18sylanb 284 . . . . . . . . . . 11 (((♯‘𝐴) ∈ ℂ ∧ (♯‘𝐵) ∈ ℂ) → ((𝐿 + (♯‘𝐵)) − 𝐿) = (♯‘𝐵))
2013, 15, 19syl2an 289 . . . . . . . . . 10 ((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) → ((𝐿 + (♯‘𝐵)) − 𝐿) = (♯‘𝐵))
2120eqcomd 2235 . . . . . . . . 9 ((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) → (♯‘𝐵) = ((𝐿 + (♯‘𝐵)) − 𝐿))
2221adantr 276 . . . . . . . 8 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → (♯‘𝐵) = ((𝐿 + (♯‘𝐵)) − 𝐿))
23223ad2ant1 1042 . . . . . . 7 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿𝐿𝑀) → (♯‘𝐵) = ((𝐿 + (♯‘𝐵)) − 𝐿))
2423opeq2d 3863 . . . . . 6 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿𝐿𝑀) → ⟨(𝑀𝐿), (♯‘𝐵)⟩ = ⟨(𝑀𝐿), ((𝐿 + (♯‘𝐵)) − 𝐿)⟩)
2524oveq2d 6016 . . . . 5 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿𝐿𝑀) → (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩) = (𝐵 substr ⟨(𝑀𝐿), ((𝐿 + (♯‘𝐵)) − 𝐿)⟩))
2611, 25eqtrd 2262 . . . 4 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿𝐿𝑀) → if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)) = (𝐵 substr ⟨(𝑀𝐿), ((𝐿 + (♯‘𝐵)) − 𝐿)⟩))
27 iffalse 3610 . . . . . 6 𝐿𝑀 → if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)) = ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵))
28273ad2ant3 1044 . . . . 5 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)) = ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵))
2920adantr 276 . . . . . . . . 9 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → ((𝐿 + (♯‘𝐵)) − 𝐿) = (♯‘𝐵))
30293ad2ant1 1042 . . . . . . . 8 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → ((𝐿 + (♯‘𝐵)) − 𝐿) = (♯‘𝐵))
3130oveq2d 6016 . . . . . . 7 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → (𝐵 prefix ((𝐿 + (♯‘𝐵)) − 𝐿)) = (𝐵 prefix (♯‘𝐵)))
32 pfxid 11213 . . . . . . . . 9 (𝐵 ∈ Word 𝑉 → (𝐵 prefix (♯‘𝐵)) = 𝐵)
3332ad2antlr 489 . . . . . . . 8 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → (𝐵 prefix (♯‘𝐵)) = 𝐵)
34333ad2ant1 1042 . . . . . . 7 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → (𝐵 prefix (♯‘𝐵)) = 𝐵)
3531, 34eqtr2d 2263 . . . . . 6 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → 𝐵 = (𝐵 prefix ((𝐿 + (♯‘𝐵)) − 𝐿)))
3635oveq2d 6016 . . . . 5 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵) = ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ (𝐵 prefix ((𝐿 + (♯‘𝐵)) − 𝐿))))
3728, 36eqtrd 2262 . . . 4 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)) = ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ (𝐵 prefix ((𝐿 + (♯‘𝐵)) − 𝐿))))
384elfzelzd 10218 . . . . 5 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → (𝐿 + (♯‘𝐵)) ∈ ℤ)
395, 12eqeltrid 2316 . . . . . . 7 (𝐴 ∈ Word 𝑉𝐿 ∈ ℕ0)
4039ad2antrr 488 . . . . . 6 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → 𝐿 ∈ ℕ0)
4140nn0zd 9563 . . . . 5 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → 𝐿 ∈ ℤ)
42 zdcle 9519 . . . . 5 (((𝐿 + (♯‘𝐵)) ∈ ℤ ∧ 𝐿 ∈ ℤ) → DECID (𝐿 + (♯‘𝐵)) ≤ 𝐿)
4338, 41, 42syl2anc 411 . . . 4 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → DECID (𝐿 + (♯‘𝐵)) ≤ 𝐿)
4441adantr 276 . . . . 5 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿) → 𝐿 ∈ ℤ)
45 elfznn0 10306 . . . . . . 7 (𝑀 ∈ (0...(𝐿 + (♯‘𝐵))) → 𝑀 ∈ ℕ0)
4645ad2antlr 489 . . . . . 6 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿) → 𝑀 ∈ ℕ0)
4746nn0zd 9563 . . . . 5 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿) → 𝑀 ∈ ℤ)
48 zdcle 9519 . . . . 5 ((𝐿 ∈ ℤ ∧ 𝑀 ∈ ℤ) → DECID 𝐿𝑀)
4944, 47, 48syl2anc 411 . . . 4 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿) → DECID 𝐿𝑀)
509, 26, 37, 43, 492if2dc 3642 . . 3 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)) = if((𝐿 + (♯‘𝐵)) ≤ 𝐿, (𝐴 substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩), if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), ((𝐿 + (♯‘𝐵)) − 𝐿)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ (𝐵 prefix ((𝐿 + (♯‘𝐵)) − 𝐿))))))
518, 50eqtr4d 2265 . 2 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → ((𝐴 ++ 𝐵) substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩) = if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)))
5251ex 115 1 ((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) → (𝑀 ∈ (0...(𝐿 + (♯‘𝐵))) → ((𝐴 ++ 𝐵) substr ⟨𝑀, (𝐿 + (♯‘𝐵))⟩) = if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵))))
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 104  DECID wdc 839  w3a 1002   = wceq 1395  wcel 2200  ifcif 3602  cop 3669   class class class wbr 4082  cfv 5317  (class class class)co 6000  cc 7993  0cc0 7995   + caddc 7998  cle 8178  cmin 8313  0cn0 9365  cz 9442  ...cfz 10200  chash 10992  Word cword 11066   ++ cconcat 11120   substr csubstr 11172   prefix cpfx 11199
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 617  ax-in2 618  ax-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-13 2202  ax-14 2203  ax-ext 2211  ax-coll 4198  ax-sep 4201  ax-nul 4209  ax-pow 4257  ax-pr 4292  ax-un 4523  ax-setind 4628  ax-iinf 4679  ax-cnex 8086  ax-resscn 8087  ax-1cn 8088  ax-1re 8089  ax-icn 8090  ax-addcl 8091  ax-addrcl 8092  ax-mulcl 8093  ax-addcom 8095  ax-addass 8097  ax-distr 8099  ax-i2m1 8100  ax-0lt1 8101  ax-0id 8103  ax-rnegex 8104  ax-cnre 8106  ax-pre-ltirr 8107  ax-pre-ltwlin 8108  ax-pre-lttrn 8109  ax-pre-apti 8110  ax-pre-ltadd 8111
This theorem depends on definitions:  df-bi 117  df-dc 840  df-3or 1003  df-3an 1004  df-tru 1398  df-fal 1401  df-nf 1507  df-sb 1809  df-eu 2080  df-mo 2081  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ne 2401  df-nel 2496  df-ral 2513  df-rex 2514  df-reu 2515  df-rab 2517  df-v 2801  df-sbc 3029  df-csb 3125  df-dif 3199  df-un 3201  df-in 3203  df-ss 3210  df-nul 3492  df-if 3603  df-pw 3651  df-sn 3672  df-pr 3673  df-op 3675  df-uni 3888  df-int 3923  df-iun 3966  df-br 4083  df-opab 4145  df-mpt 4146  df-tr 4182  df-id 4383  df-iord 4456  df-on 4458  df-ilim 4459  df-suc 4461  df-iom 4682  df-xp 4724  df-rel 4725  df-cnv 4726  df-co 4727  df-dm 4728  df-rn 4729  df-res 4730  df-ima 4731  df-iota 5277  df-fun 5319  df-fn 5320  df-f 5321  df-f1 5322  df-fo 5323  df-f1o 5324  df-fv 5325  df-riota 5953  df-ov 6003  df-oprab 6004  df-mpo 6005  df-1st 6284  df-2nd 6285  df-recs 6449  df-frec 6535  df-1o 6560  df-er 6678  df-en 6886  df-dom 6887  df-fin 6888  df-pnf 8179  df-mnf 8180  df-xr 8181  df-ltxr 8182  df-le 8183  df-sub 8315  df-neg 8316  df-inn 9107  df-n0 9366  df-z 9443  df-uz 9719  df-fz 10201  df-fzo 10335  df-ihash 10993  df-word 11067  df-concat 11121  df-substr 11173  df-pfx 11200
This theorem is referenced by: (None)
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