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Mirrors > Home > MPE Home > Th. List > ccats1pfxeqbi | Structured version Visualization version GIF version |
Description: A word is a prefix of a word with length greater by 1 than the first word iff the second word is the first word concatenated with the last symbol of the second word. (Contributed by AV, 24-Oct-2018.) (Revised by AV, 10-May-2020.) |
Ref | Expression |
---|---|
ccats1pfxeqbi | ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (𝑊 = (𝑈 prefix (♯‘𝑊)) ↔ 𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ccats1pfxeq 13831 | . 2 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (𝑊 = (𝑈 prefix (♯‘𝑊)) → 𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉))) | |
2 | simp1 1127 | . . . . 5 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → 𝑊 ∈ Word 𝑉) | |
3 | lencl 13621 | . . . . . . . . 9 ⊢ (𝑊 ∈ Word 𝑉 → (♯‘𝑊) ∈ ℕ0) | |
4 | nn0p1nn 11683 | . . . . . . . . 9 ⊢ ((♯‘𝑊) ∈ ℕ0 → ((♯‘𝑊) + 1) ∈ ℕ) | |
5 | 3, 4 | syl 17 | . . . . . . . 8 ⊢ (𝑊 ∈ Word 𝑉 → ((♯‘𝑊) + 1) ∈ ℕ) |
6 | 5 | 3ad2ant1 1124 | . . . . . . 7 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → ((♯‘𝑊) + 1) ∈ ℕ) |
7 | 3simpc 1143 | . . . . . . 7 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1))) | |
8 | lswlgt0cl 13659 | . . . . . . 7 ⊢ ((((♯‘𝑊) + 1) ∈ ℕ ∧ (𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1))) → (lastS‘𝑈) ∈ 𝑉) | |
9 | 6, 7, 8 | syl2anc 579 | . . . . . 6 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (lastS‘𝑈) ∈ 𝑉) |
10 | 9 | s1cld 13693 | . . . . 5 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → 〈“(lastS‘𝑈)”〉 ∈ Word 𝑉) |
11 | eqidd 2778 | . . . . 5 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (♯‘𝑊) = (♯‘𝑊)) | |
12 | pfxccatid 13874 | . . . . . 6 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 〈“(lastS‘𝑈)”〉 ∈ Word 𝑉 ∧ (♯‘𝑊) = (♯‘𝑊)) → ((𝑊 ++ 〈“(lastS‘𝑈)”〉) prefix (♯‘𝑊)) = 𝑊) | |
13 | 12 | eqcomd 2783 | . . . . 5 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 〈“(lastS‘𝑈)”〉 ∈ Word 𝑉 ∧ (♯‘𝑊) = (♯‘𝑊)) → 𝑊 = ((𝑊 ++ 〈“(lastS‘𝑈)”〉) prefix (♯‘𝑊))) |
14 | 2, 10, 11, 13 | syl3anc 1439 | . . . 4 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → 𝑊 = ((𝑊 ++ 〈“(lastS‘𝑈)”〉) prefix (♯‘𝑊))) |
15 | oveq1 6929 | . . . . 5 ⊢ (𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉) → (𝑈 prefix (♯‘𝑊)) = ((𝑊 ++ 〈“(lastS‘𝑈)”〉) prefix (♯‘𝑊))) | |
16 | 15 | eqcomd 2783 | . . . 4 ⊢ (𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉) → ((𝑊 ++ 〈“(lastS‘𝑈)”〉) prefix (♯‘𝑊)) = (𝑈 prefix (♯‘𝑊))) |
17 | 14, 16 | sylan9eq 2833 | . . 3 ⊢ (((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) ∧ 𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉)) → 𝑊 = (𝑈 prefix (♯‘𝑊))) |
18 | 17 | ex 403 | . 2 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉) → 𝑊 = (𝑈 prefix (♯‘𝑊)))) |
19 | 1, 18 | impbid 204 | 1 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (𝑊 = (𝑈 prefix (♯‘𝑊)) ↔ 𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉))) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 198 ∧ wa 386 ∧ w3a 1071 = wceq 1601 ∈ wcel 2106 ‘cfv 6135 (class class class)co 6922 1c1 10273 + caddc 10275 ℕcn 11374 ℕ0cn0 11642 ♯chash 13435 Word cword 13599 lastSclsw 13652 ++ cconcat 13660 〈“cs1 13685 prefix cpfx 13779 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1839 ax-4 1853 ax-5 1953 ax-6 2021 ax-7 2054 ax-8 2108 ax-9 2115 ax-10 2134 ax-11 2149 ax-12 2162 ax-13 2333 ax-ext 2753 ax-rep 5006 ax-sep 5017 ax-nul 5025 ax-pow 5077 ax-pr 5138 ax-un 7226 ax-cnex 10328 ax-resscn 10329 ax-1cn 10330 ax-icn 10331 ax-addcl 10332 ax-addrcl 10333 ax-mulcl 10334 ax-mulrcl 10335 ax-mulcom 10336 ax-addass 10337 ax-mulass 10338 ax-distr 10339 ax-i2m1 10340 ax-1ne0 10341 ax-1rid 10342 ax-rnegex 10343 ax-rrecex 10344 ax-cnre 10345 ax-pre-lttri 10346 ax-pre-lttrn 10347 ax-pre-ltadd 10348 ax-pre-mulgt0 10349 |
This theorem depends on definitions: df-bi 199 df-an 387 df-or 837 df-3or 1072 df-3an 1073 df-tru 1605 df-ex 1824 df-nf 1828 df-sb 2012 df-mo 2550 df-eu 2586 df-clab 2763 df-cleq 2769 df-clel 2773 df-nfc 2920 df-ne 2969 df-nel 3075 df-ral 3094 df-rex 3095 df-reu 3096 df-rab 3098 df-v 3399 df-sbc 3652 df-csb 3751 df-dif 3794 df-un 3796 df-in 3798 df-ss 3805 df-pss 3807 df-nul 4141 df-if 4307 df-pw 4380 df-sn 4398 df-pr 4400 df-tp 4402 df-op 4404 df-uni 4672 df-int 4711 df-iun 4755 df-br 4887 df-opab 4949 df-mpt 4966 df-tr 4988 df-id 5261 df-eprel 5266 df-po 5274 df-so 5275 df-fr 5314 df-we 5316 df-xp 5361 df-rel 5362 df-cnv 5363 df-co 5364 df-dm 5365 df-rn 5366 df-res 5367 df-ima 5368 df-pred 5933 df-ord 5979 df-on 5980 df-lim 5981 df-suc 5982 df-iota 6099 df-fun 6137 df-fn 6138 df-f 6139 df-f1 6140 df-fo 6141 df-f1o 6142 df-fv 6143 df-riota 6883 df-ov 6925 df-oprab 6926 df-mpt2 6927 df-om 7344 df-1st 7445 df-2nd 7446 df-wrecs 7689 df-recs 7751 df-rdg 7789 df-1o 7843 df-oadd 7847 df-er 8026 df-en 8242 df-dom 8243 df-sdom 8244 df-fin 8245 df-card 9098 df-pnf 10413 df-mnf 10414 df-xr 10415 df-ltxr 10416 df-le 10417 df-sub 10608 df-neg 10609 df-nn 11375 df-n0 11643 df-xnn0 11715 df-z 11729 df-uz 11993 df-fz 12644 df-fzo 12785 df-hash 13436 df-word 13600 df-lsw 13653 df-concat 13661 df-s1 13686 df-substr 13731 df-pfx 13780 |
This theorem is referenced by: (None) |
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