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Theorem pfxsuff1eqwrdeq 40270
Description: Two (nonempty) words are equal if and only if they have the same prefix and the same single symbol suffix. Could replace 2swrd1eqwrdeq 13306. (Contributed by AV, 6-May-2020.)
Assertion
Ref Expression
pfxsuff1eqwrdeq ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → (𝑊 = 𝑈 ↔ ((#‘𝑊) = (#‘𝑈) ∧ ((𝑊 prefix ((#‘𝑊) − 1)) = (𝑈 prefix ((#‘𝑊) − 1)) ∧ ( lastS ‘𝑊) = ( lastS ‘𝑈)))))

Proof of Theorem pfxsuff1eqwrdeq
StepHypRef Expression
1 hashgt0n0 13017 . . . . . 6 ((𝑊 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → 𝑊 ≠ ∅)
2 lennncl 13180 . . . . . 6 ((𝑊 ∈ Word 𝑉𝑊 ≠ ∅) → (#‘𝑊) ∈ ℕ)
31, 2syldan 486 . . . . 5 ((𝑊 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → (#‘𝑊) ∈ ℕ)
433adant2 1073 . . . 4 ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → (#‘𝑊) ∈ ℕ)
5 fzo0end 12426 . . . 4 ((#‘𝑊) ∈ ℕ → ((#‘𝑊) − 1) ∈ (0..^(#‘𝑊)))
64, 5syl 17 . . 3 ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → ((#‘𝑊) − 1) ∈ (0..^(#‘𝑊)))
7 pfxsuffeqwrdeq 40269 . . 3 ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ ((#‘𝑊) − 1) ∈ (0..^(#‘𝑊))) → (𝑊 = 𝑈 ↔ ((#‘𝑊) = (#‘𝑈) ∧ ((𝑊 prefix ((#‘𝑊) − 1)) = (𝑈 prefix ((#‘𝑊) − 1)) ∧ (𝑊 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = (𝑈 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩)))))
86, 7syld3an3 1363 . 2 ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → (𝑊 = 𝑈 ↔ ((#‘𝑊) = (#‘𝑈) ∧ ((𝑊 prefix ((#‘𝑊) − 1)) = (𝑈 prefix ((#‘𝑊) − 1)) ∧ (𝑊 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = (𝑈 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩)))))
9 hashneq0 13016 . . . . . . . . . . 11 (𝑊 ∈ Word 𝑉 → (0 < (#‘𝑊) ↔ 𝑊 ≠ ∅))
109biimpd 218 . . . . . . . . . 10 (𝑊 ∈ Word 𝑉 → (0 < (#‘𝑊) → 𝑊 ≠ ∅))
1110imdistani 722 . . . . . . . . 9 ((𝑊 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → (𝑊 ∈ Word 𝑉𝑊 ≠ ∅))
12113adant2 1073 . . . . . . . 8 ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → (𝑊 ∈ Word 𝑉𝑊 ≠ ∅))
1312adantr 480 . . . . . . 7 (((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ∧ (#‘𝑊) = (#‘𝑈)) → (𝑊 ∈ Word 𝑉𝑊 ≠ ∅))
14 swrdlsw 13304 . . . . . . 7 ((𝑊 ∈ Word 𝑉𝑊 ≠ ∅) → (𝑊 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = ⟨“( lastS ‘𝑊)”⟩)
1513, 14syl 17 . . . . . 6 (((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ∧ (#‘𝑊) = (#‘𝑈)) → (𝑊 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = ⟨“( lastS ‘𝑊)”⟩)
16 breq2 4587 . . . . . . . . . 10 ((#‘𝑊) = (#‘𝑈) → (0 < (#‘𝑊) ↔ 0 < (#‘𝑈)))
17163anbi3d 1397 . . . . . . . . 9 ((#‘𝑊) = (#‘𝑈) → ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ↔ (𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑈))))
18 hashneq0 13016 . . . . . . . . . . . . 13 (𝑈 ∈ Word 𝑉 → (0 < (#‘𝑈) ↔ 𝑈 ≠ ∅))
1918biimpd 218 . . . . . . . . . . . 12 (𝑈 ∈ Word 𝑉 → (0 < (#‘𝑈) → 𝑈 ≠ ∅))
2019imdistani 722 . . . . . . . . . . 11 ((𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑈)) → (𝑈 ∈ Word 𝑉𝑈 ≠ ∅))
21203adant1 1072 . . . . . . . . . 10 ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑈)) → (𝑈 ∈ Word 𝑉𝑈 ≠ ∅))
22 swrdlsw 13304 . . . . . . . . . 10 ((𝑈 ∈ Word 𝑉𝑈 ≠ ∅) → (𝑈 substr ⟨((#‘𝑈) − 1), (#‘𝑈)⟩) = ⟨“( lastS ‘𝑈)”⟩)
2321, 22syl 17 . . . . . . . . 9 ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑈)) → (𝑈 substr ⟨((#‘𝑈) − 1), (#‘𝑈)⟩) = ⟨“( lastS ‘𝑈)”⟩)
2417, 23syl6bi 242 . . . . . . . 8 ((#‘𝑊) = (#‘𝑈) → ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → (𝑈 substr ⟨((#‘𝑈) − 1), (#‘𝑈)⟩) = ⟨“( lastS ‘𝑈)”⟩))
2524impcom 445 . . . . . . 7 (((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ∧ (#‘𝑊) = (#‘𝑈)) → (𝑈 substr ⟨((#‘𝑈) − 1), (#‘𝑈)⟩) = ⟨“( lastS ‘𝑈)”⟩)
26 oveq1 6556 . . . . . . . . . . 11 ((#‘𝑊) = (#‘𝑈) → ((#‘𝑊) − 1) = ((#‘𝑈) − 1))
27 id 22 . . . . . . . . . . 11 ((#‘𝑊) = (#‘𝑈) → (#‘𝑊) = (#‘𝑈))
2826, 27opeq12d 4348 . . . . . . . . . 10 ((#‘𝑊) = (#‘𝑈) → ⟨((#‘𝑊) − 1), (#‘𝑊)⟩ = ⟨((#‘𝑈) − 1), (#‘𝑈)⟩)
2928oveq2d 6565 . . . . . . . . 9 ((#‘𝑊) = (#‘𝑈) → (𝑈 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = (𝑈 substr ⟨((#‘𝑈) − 1), (#‘𝑈)⟩))
3029eqeq1d 2612 . . . . . . . 8 ((#‘𝑊) = (#‘𝑈) → ((𝑈 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = ⟨“( lastS ‘𝑈)”⟩ ↔ (𝑈 substr ⟨((#‘𝑈) − 1), (#‘𝑈)⟩) = ⟨“( lastS ‘𝑈)”⟩))
3130adantl 481 . . . . . . 7 (((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ∧ (#‘𝑊) = (#‘𝑈)) → ((𝑈 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = ⟨“( lastS ‘𝑈)”⟩ ↔ (𝑈 substr ⟨((#‘𝑈) − 1), (#‘𝑈)⟩) = ⟨“( lastS ‘𝑈)”⟩))
3225, 31mpbird 246 . . . . . 6 (((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ∧ (#‘𝑊) = (#‘𝑈)) → (𝑈 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = ⟨“( lastS ‘𝑈)”⟩)
3315, 32eqeq12d 2625 . . . . 5 (((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ∧ (#‘𝑊) = (#‘𝑈)) → ((𝑊 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = (𝑈 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) ↔ ⟨“( lastS ‘𝑊)”⟩ = ⟨“( lastS ‘𝑈)”⟩))
34 fvex 6113 . . . . . . 7 ( lastS ‘𝑊) ∈ V
3534a1i 11 . . . . . 6 (((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ∧ (#‘𝑊) = (#‘𝑈)) → ( lastS ‘𝑊) ∈ V)
36 fvex 6113 . . . . . 6 ( lastS ‘𝑈) ∈ V
37 s111 13248 . . . . . 6 ((( lastS ‘𝑊) ∈ V ∧ ( lastS ‘𝑈) ∈ V) → (⟨“( lastS ‘𝑊)”⟩ = ⟨“( lastS ‘𝑈)”⟩ ↔ ( lastS ‘𝑊) = ( lastS ‘𝑈)))
3835, 36, 37sylancl 693 . . . . 5 (((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ∧ (#‘𝑊) = (#‘𝑈)) → (⟨“( lastS ‘𝑊)”⟩ = ⟨“( lastS ‘𝑈)”⟩ ↔ ( lastS ‘𝑊) = ( lastS ‘𝑈)))
3933, 38bitrd 267 . . . 4 (((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ∧ (#‘𝑊) = (#‘𝑈)) → ((𝑊 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = (𝑈 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) ↔ ( lastS ‘𝑊) = ( lastS ‘𝑈)))
4039anbi2d 736 . . 3 (((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) ∧ (#‘𝑊) = (#‘𝑈)) → (((𝑊 prefix ((#‘𝑊) − 1)) = (𝑈 prefix ((#‘𝑊) − 1)) ∧ (𝑊 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = (𝑈 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩)) ↔ ((𝑊 prefix ((#‘𝑊) − 1)) = (𝑈 prefix ((#‘𝑊) − 1)) ∧ ( lastS ‘𝑊) = ( lastS ‘𝑈))))
4140pm5.32da 671 . 2 ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → (((#‘𝑊) = (#‘𝑈) ∧ ((𝑊 prefix ((#‘𝑊) − 1)) = (𝑈 prefix ((#‘𝑊) − 1)) ∧ (𝑊 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩) = (𝑈 substr ⟨((#‘𝑊) − 1), (#‘𝑊)⟩))) ↔ ((#‘𝑊) = (#‘𝑈) ∧ ((𝑊 prefix ((#‘𝑊) − 1)) = (𝑈 prefix ((#‘𝑊) − 1)) ∧ ( lastS ‘𝑊) = ( lastS ‘𝑈)))))
428, 41bitrd 267 1 ((𝑊 ∈ Word 𝑉𝑈 ∈ Word 𝑉 ∧ 0 < (#‘𝑊)) → (𝑊 = 𝑈 ↔ ((#‘𝑊) = (#‘𝑈) ∧ ((𝑊 prefix ((#‘𝑊) − 1)) = (𝑈 prefix ((#‘𝑊) − 1)) ∧ ( lastS ‘𝑊) = ( lastS ‘𝑈)))))
Colors of variables: wff setvar class
Syntax hints:  wi 4  wb 195  wa 383  w3a 1031   = wceq 1475  wcel 1977  wne 2780  Vcvv 3173  c0 3874  cop 4131   class class class wbr 4583  cfv 5804  (class class class)co 6549  0cc0 9815  1c1 9816   < clt 9953  cmin 10145  cn 10897  ..^cfzo 12334  #chash 12979  Word cword 13146   lastS clsw 13147  ⟨“cs1 13149   substr csubstr 13150   prefix cpfx 40244
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1713  ax-4 1728  ax-5 1827  ax-6 1875  ax-7 1922  ax-8 1979  ax-9 1986  ax-10 2006  ax-11 2021  ax-12 2034  ax-13 2234  ax-ext 2590  ax-rep 4699  ax-sep 4709  ax-nul 4717  ax-pow 4769  ax-pr 4833  ax-un 6847  ax-cnex 9871  ax-resscn 9872  ax-1cn 9873  ax-icn 9874  ax-addcl 9875  ax-addrcl 9876  ax-mulcl 9877  ax-mulrcl 9878  ax-mulcom 9879  ax-addass 9880  ax-mulass 9881  ax-distr 9882  ax-i2m1 9883  ax-1ne0 9884  ax-1rid 9885  ax-rnegex 9886  ax-rrecex 9887  ax-cnre 9888  ax-pre-lttri 9889  ax-pre-lttrn 9890  ax-pre-ltadd 9891  ax-pre-mulgt0 9892
This theorem depends on definitions:  df-bi 196  df-or 384  df-an 385  df-3or 1032  df-3an 1033  df-tru 1478  df-fal 1481  df-ex 1696  df-nf 1701  df-sb 1868  df-eu 2462  df-mo 2463  df-clab 2597  df-cleq 2603  df-clel 2606  df-nfc 2740  df-ne 2782  df-nel 2783  df-ral 2901  df-rex 2902  df-reu 2903  df-rab 2905  df-v 3175  df-sbc 3403  df-csb 3500  df-dif 3543  df-un 3545  df-in 3547  df-ss 3554  df-pss 3556  df-nul 3875  df-if 4037  df-pw 4110  df-sn 4126  df-pr 4128  df-tp 4130  df-op 4132  df-uni 4373  df-int 4411  df-iun 4457  df-br 4584  df-opab 4644  df-mpt 4645  df-tr 4681  df-eprel 4949  df-id 4953  df-po 4959  df-so 4960  df-fr 4997  df-we 4999  df-xp 5044  df-rel 5045  df-cnv 5046  df-co 5047  df-dm 5048  df-rn 5049  df-res 5050  df-ima 5051  df-pred 5597  df-ord 5643  df-on 5644  df-lim 5645  df-suc 5646  df-iota 5768  df-fun 5806  df-fn 5807  df-f 5808  df-f1 5809  df-fo 5810  df-f1o 5811  df-fv 5812  df-riota 6511  df-ov 6552  df-oprab 6553  df-mpt2 6554  df-om 6958  df-1st 7059  df-2nd 7060  df-wrecs 7294  df-recs 7355  df-rdg 7393  df-1o 7447  df-oadd 7451  df-er 7629  df-en 7842  df-dom 7843  df-sdom 7844  df-fin 7845  df-card 8648  df-pnf 9955  df-mnf 9956  df-xr 9957  df-ltxr 9958  df-le 9959  df-sub 10147  df-neg 10148  df-nn 10898  df-n0 11170  df-xnn0 11241  df-z 11255  df-uz 11564  df-fz 12198  df-fzo 12335  df-hash 12980  df-word 13154  df-lsw 13155  df-s1 13157  df-substr 13158  df-pfx 40245
This theorem is referenced by: (None)
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