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Mirrors > Home > MPE Home > Th. List > Mathboxes > lswn0 | Structured version Visualization version GIF version |
Description: The last symbol of a not empty word exists. The empty set must be excluded as symbol, because otherwise, it cannot be distinguished between valid cases (∅ is the last symbol) and invalid cases (∅ means that no last symbol exists. This is because of the special definition of a function in set.mm. (Contributed by Alexander van der Vekens, 18-Mar-2018.) |
Ref | Expression |
---|---|
lswn0 | ⊢ ((𝑊 ∈ Word 𝑉 ∧ ∅ ∉ 𝑉 ∧ (#‘𝑊) ≠ 0) → ( lastS ‘𝑊) ≠ ∅) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | lsw 13204 | . . 3 ⊢ (𝑊 ∈ Word 𝑉 → ( lastS ‘𝑊) = (𝑊‘((#‘𝑊) − 1))) | |
2 | 1 | 3ad2ant1 1075 | . 2 ⊢ ((𝑊 ∈ Word 𝑉 ∧ ∅ ∉ 𝑉 ∧ (#‘𝑊) ≠ 0) → ( lastS ‘𝑊) = (𝑊‘((#‘𝑊) − 1))) |
3 | wrdf 13165 | . . . . . 6 ⊢ (𝑊 ∈ Word 𝑉 → 𝑊:(0..^(#‘𝑊))⟶𝑉) | |
4 | lencl 13179 | . . . . . 6 ⊢ (𝑊 ∈ Word 𝑉 → (#‘𝑊) ∈ ℕ0) | |
5 | simpll 786 | . . . . . . . 8 ⊢ (((𝑊:(0..^(#‘𝑊))⟶𝑉 ∧ (#‘𝑊) ∈ ℕ0) ∧ (#‘𝑊) ≠ 0) → 𝑊:(0..^(#‘𝑊))⟶𝑉) | |
6 | elnnne0 11183 | . . . . . . . . . . . 12 ⊢ ((#‘𝑊) ∈ ℕ ↔ ((#‘𝑊) ∈ ℕ0 ∧ (#‘𝑊) ≠ 0)) | |
7 | 6 | biimpri 217 | . . . . . . . . . . 11 ⊢ (((#‘𝑊) ∈ ℕ0 ∧ (#‘𝑊) ≠ 0) → (#‘𝑊) ∈ ℕ) |
8 | nnm1nn0 11211 | . . . . . . . . . . 11 ⊢ ((#‘𝑊) ∈ ℕ → ((#‘𝑊) − 1) ∈ ℕ0) | |
9 | 7, 8 | syl 17 | . . . . . . . . . 10 ⊢ (((#‘𝑊) ∈ ℕ0 ∧ (#‘𝑊) ≠ 0) → ((#‘𝑊) − 1) ∈ ℕ0) |
10 | nn0re 11178 | . . . . . . . . . . . 12 ⊢ ((#‘𝑊) ∈ ℕ0 → (#‘𝑊) ∈ ℝ) | |
11 | 10 | ltm1d 10835 | . . . . . . . . . . 11 ⊢ ((#‘𝑊) ∈ ℕ0 → ((#‘𝑊) − 1) < (#‘𝑊)) |
12 | 11 | adantr 480 | . . . . . . . . . 10 ⊢ (((#‘𝑊) ∈ ℕ0 ∧ (#‘𝑊) ≠ 0) → ((#‘𝑊) − 1) < (#‘𝑊)) |
13 | elfzo0 12376 | . . . . . . . . . 10 ⊢ (((#‘𝑊) − 1) ∈ (0..^(#‘𝑊)) ↔ (((#‘𝑊) − 1) ∈ ℕ0 ∧ (#‘𝑊) ∈ ℕ ∧ ((#‘𝑊) − 1) < (#‘𝑊))) | |
14 | 9, 7, 12, 13 | syl3anbrc 1239 | . . . . . . . . 9 ⊢ (((#‘𝑊) ∈ ℕ0 ∧ (#‘𝑊) ≠ 0) → ((#‘𝑊) − 1) ∈ (0..^(#‘𝑊))) |
15 | 14 | adantll 746 | . . . . . . . 8 ⊢ (((𝑊:(0..^(#‘𝑊))⟶𝑉 ∧ (#‘𝑊) ∈ ℕ0) ∧ (#‘𝑊) ≠ 0) → ((#‘𝑊) − 1) ∈ (0..^(#‘𝑊))) |
16 | 5, 15 | ffvelrnd 6268 | . . . . . . 7 ⊢ (((𝑊:(0..^(#‘𝑊))⟶𝑉 ∧ (#‘𝑊) ∈ ℕ0) ∧ (#‘𝑊) ≠ 0) → (𝑊‘((#‘𝑊) − 1)) ∈ 𝑉) |
17 | 16 | ex 449 | . . . . . 6 ⊢ ((𝑊:(0..^(#‘𝑊))⟶𝑉 ∧ (#‘𝑊) ∈ ℕ0) → ((#‘𝑊) ≠ 0 → (𝑊‘((#‘𝑊) − 1)) ∈ 𝑉)) |
18 | 3, 4, 17 | syl2anc 691 | . . . . 5 ⊢ (𝑊 ∈ Word 𝑉 → ((#‘𝑊) ≠ 0 → (𝑊‘((#‘𝑊) − 1)) ∈ 𝑉)) |
19 | eleq1a 2683 | . . . . . . . . . 10 ⊢ ((𝑊‘((#‘𝑊) − 1)) ∈ 𝑉 → (∅ = (𝑊‘((#‘𝑊) − 1)) → ∅ ∈ 𝑉)) | |
20 | 19 | com12 32 | . . . . . . . . 9 ⊢ (∅ = (𝑊‘((#‘𝑊) − 1)) → ((𝑊‘((#‘𝑊) − 1)) ∈ 𝑉 → ∅ ∈ 𝑉)) |
21 | 20 | eqcoms 2618 | . . . . . . . 8 ⊢ ((𝑊‘((#‘𝑊) − 1)) = ∅ → ((𝑊‘((#‘𝑊) − 1)) ∈ 𝑉 → ∅ ∈ 𝑉)) |
22 | 21 | com12 32 | . . . . . . 7 ⊢ ((𝑊‘((#‘𝑊) − 1)) ∈ 𝑉 → ((𝑊‘((#‘𝑊) − 1)) = ∅ → ∅ ∈ 𝑉)) |
23 | nnel 2892 | . . . . . . 7 ⊢ (¬ ∅ ∉ 𝑉 ↔ ∅ ∈ 𝑉) | |
24 | 22, 23 | syl6ibr 241 | . . . . . 6 ⊢ ((𝑊‘((#‘𝑊) − 1)) ∈ 𝑉 → ((𝑊‘((#‘𝑊) − 1)) = ∅ → ¬ ∅ ∉ 𝑉)) |
25 | 24 | necon2ad 2797 | . . . . 5 ⊢ ((𝑊‘((#‘𝑊) − 1)) ∈ 𝑉 → (∅ ∉ 𝑉 → (𝑊‘((#‘𝑊) − 1)) ≠ ∅)) |
26 | 18, 25 | syl6 34 | . . . 4 ⊢ (𝑊 ∈ Word 𝑉 → ((#‘𝑊) ≠ 0 → (∅ ∉ 𝑉 → (𝑊‘((#‘𝑊) − 1)) ≠ ∅))) |
27 | 26 | com23 84 | . . 3 ⊢ (𝑊 ∈ Word 𝑉 → (∅ ∉ 𝑉 → ((#‘𝑊) ≠ 0 → (𝑊‘((#‘𝑊) − 1)) ≠ ∅))) |
28 | 27 | 3imp 1249 | . 2 ⊢ ((𝑊 ∈ Word 𝑉 ∧ ∅ ∉ 𝑉 ∧ (#‘𝑊) ≠ 0) → (𝑊‘((#‘𝑊) − 1)) ≠ ∅) |
29 | 2, 28 | eqnetrd 2849 | 1 ⊢ ((𝑊 ∈ Word 𝑉 ∧ ∅ ∉ 𝑉 ∧ (#‘𝑊) ≠ 0) → ( lastS ‘𝑊) ≠ ∅) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 383 ∧ w3a 1031 = wceq 1475 ∈ wcel 1977 ≠ wne 2780 ∉ wnel 2781 ∅c0 3874 class class class wbr 4583 ⟶wf 5800 ‘cfv 5804 (class class class)co 6549 0cc0 9815 1c1 9816 < clt 9953 − cmin 10145 ℕcn 10897 ℕ0cn0 11169 ..^cfzo 12334 #chash 12979 Word cword 13146 lastS clsw 13147 |
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-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-z 11255 df-uz 11564 df-fz 12198 df-fzo 12335 df-hash 12980 df-word 13154 df-lsw 13155 |
This theorem is referenced by: (None) |
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