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Theorem swrdccat3b 11512
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 10440 . . . . 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 11506 . . . . 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 1276 . . 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 11511 . . . 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 3645 . . . . . 6 (𝐿𝑀 → if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)) = (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩))
11103ad2ant3 1051 . . . . 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 11308 . . . . . . . . . . . 12 (𝐴 ∈ Word 𝑉 → (♯‘𝐴) ∈ ℕ0)
1312nn0cnd 9622 . . . . . . . . . . 11 (𝐴 ∈ Word 𝑉 → (♯‘𝐴) ∈ ℂ)
14 lencl 11308 . . . . . . . . . . . 12 (𝐵 ∈ Word 𝑉 → (♯‘𝐵) ∈ ℕ0)
1514nn0cnd 9622 . . . . . . . . . . 11 (𝐵 ∈ Word 𝑉 → (♯‘𝐵) ∈ ℂ)
165eqcomi 2242 . . . . . . . . . . . . 13 (♯‘𝐴) = 𝐿
1716eleq1i 2304 . . . . . . . . . . . 12 ((♯‘𝐴) ∈ ℂ ↔ 𝐿 ∈ ℂ)
18 pncan2 8533 . . . . . . . . . . . 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 2244 . . . . . . . . 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 1049 . . . . . . 7 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿𝐿𝑀) → (♯‘𝐵) = ((𝐿 + (♯‘𝐵)) − 𝐿))
2423opeq2d 3911 . . . . . 6 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿𝐿𝑀) → ⟨(𝑀𝐿), (♯‘𝐵)⟩ = ⟨(𝑀𝐿), ((𝐿 + (♯‘𝐵)) − 𝐿)⟩)
2524oveq2d 6101 . . . . 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 2271 . . . 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 3648 . . . . . 6 𝐿𝑀 → if(𝐿𝑀, (𝐵 substr ⟨(𝑀𝐿), (♯‘𝐵)⟩), ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵)) = ((𝐴 substr ⟨𝑀, 𝐿⟩) ++ 𝐵))
28273ad2ant3 1051 . . . . 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 1049 . . . . . . . 8 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → ((𝐿 + (♯‘𝐵)) − 𝐿) = (♯‘𝐵))
3130oveq2d 6101 . . . . . . 7 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → (𝐵 prefix ((𝐿 + (♯‘𝐵)) − 𝐿)) = (𝐵 prefix (♯‘𝐵)))
32 pfxid 11458 . . . . . . . . 9 (𝐵 ∈ Word 𝑉 → (𝐵 prefix (♯‘𝐵)) = 𝐵)
3332ad2antlr 493 . . . . . . . 8 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → (𝐵 prefix (♯‘𝐵)) = 𝐵)
34333ad2ant1 1049 . . . . . . 7 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → (𝐵 prefix (♯‘𝐵)) = 𝐵)
3531, 34eqtr2d 2272 . . . . . 6 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿 ∧ ¬ 𝐿𝑀) → 𝐵 = (𝐵 prefix ((𝐿 + (♯‘𝐵)) − 𝐿)))
3635oveq2d 6101 . . . . 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 2271 . . . 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 10429 . . . . 5 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → (𝐿 + (♯‘𝐵)) ∈ ℤ)
395, 12eqeltrid 2325 . . . . . . 7 (𝐴 ∈ Word 𝑉𝐿 ∈ ℕ0)
4039ad2antrr 492 . . . . . 6 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → 𝐿 ∈ ℕ0)
4140nn0zd 9766 . . . . 5 (((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) → 𝐿 ∈ ℤ)
42 zdcle 9721 . . . . 5 (((𝐿 + (♯‘𝐵)) ∈ ℤ ∧ 𝐿 ∈ ℤ) → DECID (𝐿 + (♯‘𝐵)) ≤ 𝐿)
4338, 41, 42syl2anc 415 . . . 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 10521 . . . . . . 7 (𝑀 ∈ (0...(𝐿 + (♯‘𝐵))) → 𝑀 ∈ ℕ0)
4645ad2antlr 493 . . . . . 6 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿) → 𝑀 ∈ ℕ0)
4746nn0zd 9766 . . . . 5 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿) → 𝑀 ∈ ℤ)
48 zdcle 9721 . . . . 5 ((𝐿 ∈ ℤ ∧ 𝑀 ∈ ℤ) → DECID 𝐿𝑀)
4944, 47, 48syl2anc 415 . . . 4 ((((𝐴 ∈ Word 𝑉𝐵 ∈ Word 𝑉) ∧ 𝑀 ∈ (0...(𝐿 + (♯‘𝐵)))) ∧ ¬ (𝐿 + (♯‘𝐵)) ≤ 𝐿) → DECID 𝐿𝑀)
509, 26, 37, 43, 492if2dc 3680 . . 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 2274 . 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
This proof depends on syntax axioms:  ¬ wn 3  wi 4  wa 104  DECID wdc 846  w3a 1009   = wceq 1402  wcel 2209  ifcif 3638  cop 3712   class class class wbr 4130  cfv 5377  (class class class)co 6085  cc 8177  0cc0 8179   + caddc 8182  cle 8361  cmin 8497  0cn0 9563  cz 9644  ...cfz 10411  chash 11214  Word cword 11304   ++ cconcat 11358   substr csubstr 11417   prefix cpfx 11444
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-coll 4246  ax-sep 4249  ax-nul 4259  ax-pow 4311  ax-pr 4346  ax-un 4578  ax-setind 4684  ax-iinf 4735  ax-cnex 8270  ax-resscn 8271  ax-1cn 8272  ax-1re 8273  ax-icn 8274  ax-addcl 8275  ax-addrcl 8276  ax-mulcl 8277  ax-addcom 8279  ax-addass 8281  ax-distr 8283  ax-i2m1 8284  ax-0lt1 8285  ax-0id 8287  ax-rnegex 8288  ax-cnre 8290  ax-pre-ltirr 8291  ax-pre-ltwlin 8292  ax-pre-lttrn 8293  ax-pre-apti 8294  ax-pre-ltadd 8295
This proof depends on definitions:  df-bi 117  df-dc 847  df-3or 1010  df-3an 1011  df-tru 1405  df-fal 1408  df-nf 1514  df-sb 1816  df-eu 2089  df-mo 2090  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ne 2421  df-nel 2516  df-ral 2533  df-rex 2534  df-reu 2535  df-rab 2537  df-v 2823  df-sbc 3052  df-csb 3148  df-dif 3222  df-un 3224  df-in 3226  df-ss 3233  df-nul 3521  df-if 3639  df-pw 3690  df-sn 3715  df-pr 3716  df-op 3718  df-uni 3936  df-int 3971  df-iun 4014  df-br 4131  df-opab 4193  df-mpt 4194  df-tr 4230  df-id 4438  df-iord 4511  df-on 4513  df-ilim 4514  df-suc 4516  df-iom 4738  df-xp 4780  df-rel 4781  df-cnv 4782  df-co 4783  df-dm 4784  df-rn 4785  df-res 4786  df-ima 4787  df-iota 5337  df-fun 5379  df-fn 5380  df-f 5381  df-f1 5382  df-fo 5383  df-f1o 5384  df-fv 5385  df-riota 6038  df-ov 6088  df-oprab 6089  df-mpo 6090  df-1st 6374  df-2nd 6375  df-recs 6576  df-frec 6662  df-1o 6687  df-er 6807  df-en 7023  df-dom 7024  df-fin 7025  df-pnf 8362  df-mnf 8363  df-xr 8364  df-ltxr 8365  df-le 8366  df-sub 8499  df-neg 8500  df-inn 9305  df-n0 9564  df-z 9645  df-uz 9922  df-fz 10412  df-fzo 10550  df-ihash 11215  df-word 11305  df-concat 11359  df-substr 11418  df-pfx 11445
This theorem is used by: (None)
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