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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 14567 | . . 3 ⊢ (𝑊 ∈ Word 𝑉 → (lastS‘𝑊) = (𝑊‘((♯‘𝑊) − 1))) | |
2 | 1 | 3ad2ant1 1130 | . 2 ⊢ ((𝑊 ∈ Word 𝑉 ∧ ∅ ∉ 𝑉 ∧ (♯‘𝑊) ≠ 0) → (lastS‘𝑊) = (𝑊‘((♯‘𝑊) − 1))) |
3 | wrdf 14522 | . . . . . 6 ⊢ (𝑊 ∈ Word 𝑉 → 𝑊:(0..^(♯‘𝑊))⟶𝑉) | |
4 | lencl 14536 | . . . . . 6 ⊢ (𝑊 ∈ Word 𝑉 → (♯‘𝑊) ∈ ℕ0) | |
5 | simpll 765 | . . . . . . . 8 ⊢ (((𝑊:(0..^(♯‘𝑊))⟶𝑉 ∧ (♯‘𝑊) ∈ ℕ0) ∧ (♯‘𝑊) ≠ 0) → 𝑊:(0..^(♯‘𝑊))⟶𝑉) | |
6 | elnnne0 12532 | . . . . . . . . . . . 12 ⊢ ((♯‘𝑊) ∈ ℕ ↔ ((♯‘𝑊) ∈ ℕ0 ∧ (♯‘𝑊) ≠ 0)) | |
7 | 6 | biimpri 227 | . . . . . . . . . . 11 ⊢ (((♯‘𝑊) ∈ ℕ0 ∧ (♯‘𝑊) ≠ 0) → (♯‘𝑊) ∈ ℕ) |
8 | nnm1nn0 12559 | . . . . . . . . . . 11 ⊢ ((♯‘𝑊) ∈ ℕ → ((♯‘𝑊) − 1) ∈ ℕ0) | |
9 | 7, 8 | syl 17 | . . . . . . . . . 10 ⊢ (((♯‘𝑊) ∈ ℕ0 ∧ (♯‘𝑊) ≠ 0) → ((♯‘𝑊) − 1) ∈ ℕ0) |
10 | nn0re 12527 | . . . . . . . . . . . 12 ⊢ ((♯‘𝑊) ∈ ℕ0 → (♯‘𝑊) ∈ ℝ) | |
11 | 10 | ltm1d 12192 | . . . . . . . . . . 11 ⊢ ((♯‘𝑊) ∈ ℕ0 → ((♯‘𝑊) − 1) < (♯‘𝑊)) |
12 | 11 | adantr 479 | . . . . . . . . . 10 ⊢ (((♯‘𝑊) ∈ ℕ0 ∧ (♯‘𝑊) ≠ 0) → ((♯‘𝑊) − 1) < (♯‘𝑊)) |
13 | elfzo0 13721 | . . . . . . . . . 10 ⊢ (((♯‘𝑊) − 1) ∈ (0..^(♯‘𝑊)) ↔ (((♯‘𝑊) − 1) ∈ ℕ0 ∧ (♯‘𝑊) ∈ ℕ ∧ ((♯‘𝑊) − 1) < (♯‘𝑊))) | |
14 | 9, 7, 12, 13 | syl3anbrc 1340 | . . . . . . . . 9 ⊢ (((♯‘𝑊) ∈ ℕ0 ∧ (♯‘𝑊) ≠ 0) → ((♯‘𝑊) − 1) ∈ (0..^(♯‘𝑊))) |
15 | 14 | adantll 712 | . . . . . . . 8 ⊢ (((𝑊:(0..^(♯‘𝑊))⟶𝑉 ∧ (♯‘𝑊) ∈ ℕ0) ∧ (♯‘𝑊) ≠ 0) → ((♯‘𝑊) − 1) ∈ (0..^(♯‘𝑊))) |
16 | 5, 15 | ffvelcdmd 7091 | . . . . . . 7 ⊢ (((𝑊:(0..^(♯‘𝑊))⟶𝑉 ∧ (♯‘𝑊) ∈ ℕ0) ∧ (♯‘𝑊) ≠ 0) → (𝑊‘((♯‘𝑊) − 1)) ∈ 𝑉) |
17 | 16 | ex 411 | . . . . . 6 ⊢ ((𝑊:(0..^(♯‘𝑊))⟶𝑉 ∧ (♯‘𝑊) ∈ ℕ0) → ((♯‘𝑊) ≠ 0 → (𝑊‘((♯‘𝑊) − 1)) ∈ 𝑉)) |
18 | 3, 4, 17 | syl2anc 582 | . . . . 5 ⊢ (𝑊 ∈ Word 𝑉 → ((♯‘𝑊) ≠ 0 → (𝑊‘((♯‘𝑊) − 1)) ∈ 𝑉)) |
19 | eleq1a 2821 | . . . . . . . . . 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 2734 | . . . . . . . 8 ⊢ ((𝑊‘((♯‘𝑊) − 1)) = ∅ → ((𝑊‘((♯‘𝑊) − 1)) ∈ 𝑉 → ∅ ∈ 𝑉)) |
22 | 21 | com12 32 | . . . . . . 7 ⊢ ((𝑊‘((♯‘𝑊) − 1)) ∈ 𝑉 → ((𝑊‘((♯‘𝑊) − 1)) = ∅ → ∅ ∈ 𝑉)) |
23 | nnel 3046 | . . . . . . 7 ⊢ (¬ ∅ ∉ 𝑉 ↔ ∅ ∈ 𝑉) | |
24 | 22, 23 | imbitrrdi 251 | . . . . . 6 ⊢ ((𝑊‘((♯‘𝑊) − 1)) ∈ 𝑉 → ((𝑊‘((♯‘𝑊) − 1)) = ∅ → ¬ ∅ ∉ 𝑉)) |
25 | 24 | necon2ad 2945 | . . . . 5 ⊢ ((𝑊‘((♯‘𝑊) − 1)) ∈ 𝑉 → (∅ ∉ 𝑉 → (𝑊‘((♯‘𝑊) − 1)) ≠ ∅)) |
26 | 18, 25 | syl6 35 | . . . 4 ⊢ (𝑊 ∈ Word 𝑉 → ((♯‘𝑊) ≠ 0 → (∅ ∉ 𝑉 → (𝑊‘((♯‘𝑊) − 1)) ≠ ∅))) |
27 | 26 | com23 86 | . . 3 ⊢ (𝑊 ∈ Word 𝑉 → (∅ ∉ 𝑉 → ((♯‘𝑊) ≠ 0 → (𝑊‘((♯‘𝑊) − 1)) ≠ ∅))) |
28 | 27 | 3imp 1108 | . 2 ⊢ ((𝑊 ∈ Word 𝑉 ∧ ∅ ∉ 𝑉 ∧ (♯‘𝑊) ≠ 0) → (𝑊‘((♯‘𝑊) − 1)) ≠ ∅) |
29 | 2, 28 | eqnetrd 2998 | 1 ⊢ ((𝑊 ∈ Word 𝑉 ∧ ∅ ∉ 𝑉 ∧ (♯‘𝑊) ≠ 0) → (lastS‘𝑊) ≠ ∅) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 394 ∧ w3a 1084 = wceq 1534 ∈ wcel 2099 ≠ wne 2930 ∉ wnel 3036 ∅c0 4322 class class class wbr 5145 ⟶wf 6542 ‘cfv 6546 (class class class)co 7416 0cc0 11149 1c1 11150 < clt 11289 − cmin 11485 ℕcn 12258 ℕ0cn0 12518 ..^cfzo 13675 ♯chash 14342 Word cword 14517 lastSclsw 14565 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1790 ax-4 1804 ax-5 1906 ax-6 1964 ax-7 2004 ax-8 2101 ax-9 2109 ax-10 2130 ax-11 2147 ax-12 2167 ax-ext 2697 ax-rep 5282 ax-sep 5296 ax-nul 5303 ax-pow 5361 ax-pr 5425 ax-un 7738 ax-cnex 11205 ax-resscn 11206 ax-1cn 11207 ax-icn 11208 ax-addcl 11209 ax-addrcl 11210 ax-mulcl 11211 ax-mulrcl 11212 ax-mulcom 11213 ax-addass 11214 ax-mulass 11215 ax-distr 11216 ax-i2m1 11217 ax-1ne0 11218 ax-1rid 11219 ax-rnegex 11220 ax-rrecex 11221 ax-cnre 11222 ax-pre-lttri 11223 ax-pre-lttrn 11224 ax-pre-ltadd 11225 ax-pre-mulgt0 11226 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 846 df-3or 1085 df-3an 1086 df-tru 1537 df-fal 1547 df-ex 1775 df-nf 1779 df-sb 2061 df-mo 2529 df-eu 2558 df-clab 2704 df-cleq 2718 df-clel 2803 df-nfc 2878 df-ne 2931 df-nel 3037 df-ral 3052 df-rex 3061 df-reu 3365 df-rab 3420 df-v 3464 df-sbc 3776 df-csb 3892 df-dif 3949 df-un 3951 df-in 3953 df-ss 3963 df-pss 3966 df-nul 4323 df-if 4524 df-pw 4599 df-sn 4624 df-pr 4626 df-op 4630 df-uni 4906 df-int 4947 df-iun 4995 df-br 5146 df-opab 5208 df-mpt 5229 df-tr 5263 df-id 5572 df-eprel 5578 df-po 5586 df-so 5587 df-fr 5629 df-we 5631 df-xp 5680 df-rel 5681 df-cnv 5682 df-co 5683 df-dm 5684 df-rn 5685 df-res 5686 df-ima 5687 df-pred 6304 df-ord 6371 df-on 6372 df-lim 6373 df-suc 6374 df-iota 6498 df-fun 6548 df-fn 6549 df-f 6550 df-f1 6551 df-fo 6552 df-f1o 6553 df-fv 6554 df-riota 7372 df-ov 7419 df-oprab 7420 df-mpo 7421 df-om 7869 df-1st 7995 df-2nd 7996 df-frecs 8288 df-wrecs 8319 df-recs 8393 df-rdg 8432 df-1o 8488 df-er 8726 df-en 8967 df-dom 8968 df-sdom 8969 df-fin 8970 df-card 9975 df-pnf 11291 df-mnf 11292 df-xr 11293 df-ltxr 11294 df-le 11295 df-sub 11487 df-neg 11488 df-nn 12259 df-n0 12519 df-z 12605 df-uz 12869 df-fz 13533 df-fzo 13676 df-hash 14343 df-word 14518 df-lsw 14566 |
This theorem is referenced by: (None) |
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