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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 14408 | . 2 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (𝑊 = (𝑈 prefix (♯‘𝑊)) → 𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉))) | |
2 | simp1 1134 | . . . . 5 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → 𝑊 ∈ Word 𝑉) | |
3 | lencl 14217 | . . . . . . . . 9 ⊢ (𝑊 ∈ Word 𝑉 → (♯‘𝑊) ∈ ℕ0) | |
4 | nn0p1nn 12255 | . . . . . . . . 9 ⊢ ((♯‘𝑊) ∈ ℕ0 → ((♯‘𝑊) + 1) ∈ ℕ) | |
5 | 3, 4 | syl 17 | . . . . . . . 8 ⊢ (𝑊 ∈ Word 𝑉 → ((♯‘𝑊) + 1) ∈ ℕ) |
6 | 5 | 3ad2ant1 1131 | . . . . . . 7 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → ((♯‘𝑊) + 1) ∈ ℕ) |
7 | 3simpc 1148 | . . . . . . 7 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1))) | |
8 | lswlgt0cl 14253 | . . . . . . 7 ⊢ ((((♯‘𝑊) + 1) ∈ ℕ ∧ (𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1))) → (lastS‘𝑈) ∈ 𝑉) | |
9 | 6, 7, 8 | syl2anc 583 | . . . . . 6 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (lastS‘𝑈) ∈ 𝑉) |
10 | 9 | s1cld 14289 | . . . . 5 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → 〈“(lastS‘𝑈)”〉 ∈ Word 𝑉) |
11 | eqidd 2740 | . . . . 5 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (♯‘𝑊) = (♯‘𝑊)) | |
12 | pfxccatid 14435 | . . . . . 6 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 〈“(lastS‘𝑈)”〉 ∈ Word 𝑉 ∧ (♯‘𝑊) = (♯‘𝑊)) → ((𝑊 ++ 〈“(lastS‘𝑈)”〉) prefix (♯‘𝑊)) = 𝑊) | |
13 | 12 | eqcomd 2745 | . . . . 5 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 〈“(lastS‘𝑈)”〉 ∈ Word 𝑉 ∧ (♯‘𝑊) = (♯‘𝑊)) → 𝑊 = ((𝑊 ++ 〈“(lastS‘𝑈)”〉) prefix (♯‘𝑊))) |
14 | 2, 10, 11, 13 | syl3anc 1369 | . . . 4 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → 𝑊 = ((𝑊 ++ 〈“(lastS‘𝑈)”〉) prefix (♯‘𝑊))) |
15 | oveq1 7275 | . . . . 5 ⊢ (𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉) → (𝑈 prefix (♯‘𝑊)) = ((𝑊 ++ 〈“(lastS‘𝑈)”〉) prefix (♯‘𝑊))) | |
16 | 15 | eqcomd 2745 | . . . 4 ⊢ (𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉) → ((𝑊 ++ 〈“(lastS‘𝑈)”〉) prefix (♯‘𝑊)) = (𝑈 prefix (♯‘𝑊))) |
17 | 14, 16 | sylan9eq 2799 | . . 3 ⊢ (((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) ∧ 𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉)) → 𝑊 = (𝑈 prefix (♯‘𝑊))) |
18 | 17 | ex 412 | . 2 ⊢ ((𝑊 ∈ Word 𝑉 ∧ 𝑈 ∈ Word 𝑉 ∧ (♯‘𝑈) = ((♯‘𝑊) + 1)) → (𝑈 = (𝑊 ++ 〈“(lastS‘𝑈)”〉) → 𝑊 = (𝑈 prefix (♯‘𝑊)))) |
19 | 1, 18 | impbid 211 | 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 205 ∧ wa 395 ∧ w3a 1085 = wceq 1541 ∈ wcel 2109 ‘cfv 6430 (class class class)co 7268 1c1 10856 + caddc 10858 ℕcn 11956 ℕ0cn0 12216 ♯chash 14025 Word cword 14198 lastSclsw 14246 ++ cconcat 14254 〈“cs1 14281 prefix cpfx 14364 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1801 ax-4 1815 ax-5 1916 ax-6 1974 ax-7 2014 ax-8 2111 ax-9 2119 ax-10 2140 ax-11 2157 ax-12 2174 ax-ext 2710 ax-rep 5213 ax-sep 5226 ax-nul 5233 ax-pow 5291 ax-pr 5355 ax-un 7579 ax-cnex 10911 ax-resscn 10912 ax-1cn 10913 ax-icn 10914 ax-addcl 10915 ax-addrcl 10916 ax-mulcl 10917 ax-mulrcl 10918 ax-mulcom 10919 ax-addass 10920 ax-mulass 10921 ax-distr 10922 ax-i2m1 10923 ax-1ne0 10924 ax-1rid 10925 ax-rnegex 10926 ax-rrecex 10927 ax-cnre 10928 ax-pre-lttri 10929 ax-pre-lttrn 10930 ax-pre-ltadd 10931 ax-pre-mulgt0 10932 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 844 df-3or 1086 df-3an 1087 df-tru 1544 df-fal 1554 df-ex 1786 df-nf 1790 df-sb 2071 df-mo 2541 df-eu 2570 df-clab 2717 df-cleq 2731 df-clel 2817 df-nfc 2890 df-ne 2945 df-nel 3051 df-ral 3070 df-rex 3071 df-reu 3072 df-rab 3074 df-v 3432 df-sbc 3720 df-csb 3837 df-dif 3894 df-un 3896 df-in 3898 df-ss 3908 df-pss 3910 df-nul 4262 df-if 4465 df-pw 4540 df-sn 4567 df-pr 4569 df-tp 4571 df-op 4573 df-uni 4845 df-int 4885 df-iun 4931 df-br 5079 df-opab 5141 df-mpt 5162 df-tr 5196 df-id 5488 df-eprel 5494 df-po 5502 df-so 5503 df-fr 5543 df-we 5545 df-xp 5594 df-rel 5595 df-cnv 5596 df-co 5597 df-dm 5598 df-rn 5599 df-res 5600 df-ima 5601 df-pred 6199 df-ord 6266 df-on 6267 df-lim 6268 df-suc 6269 df-iota 6388 df-fun 6432 df-fn 6433 df-f 6434 df-f1 6435 df-fo 6436 df-f1o 6437 df-fv 6438 df-riota 7225 df-ov 7271 df-oprab 7272 df-mpo 7273 df-om 7701 df-1st 7817 df-2nd 7818 df-frecs 8081 df-wrecs 8112 df-recs 8186 df-rdg 8225 df-1o 8281 df-er 8472 df-en 8708 df-dom 8709 df-sdom 8710 df-fin 8711 df-card 9681 df-pnf 10995 df-mnf 10996 df-xr 10997 df-ltxr 10998 df-le 10999 df-sub 11190 df-neg 11191 df-nn 11957 df-n0 12217 df-xnn0 12289 df-z 12303 df-uz 12565 df-fz 13222 df-fzo 13365 df-hash 14026 df-word 14199 df-lsw 14247 df-concat 14255 df-s1 14282 df-substr 14335 df-pfx 14365 |
This theorem is referenced by: (None) |
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