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Mirrors > Home > MPE Home > Th. List > hashneq0 | Structured version Visualization version GIF version |
Description: Two ways of saying a set is not empty. (Contributed by Alexander van der Vekens, 23-Sep-2018.) |
Ref | Expression |
---|---|
hashneq0 | ⊢ (𝐴 ∈ 𝑉 → (0 < (♯‘𝐴) ↔ 𝐴 ≠ ∅)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | hashnn0pnf 14307 | . . 3 ⊢ (𝐴 ∈ 𝑉 → ((♯‘𝐴) ∈ ℕ0 ∨ (♯‘𝐴) = +∞)) | |
2 | nn0re 12485 | . . . . . 6 ⊢ ((♯‘𝐴) ∈ ℕ0 → (♯‘𝐴) ∈ ℝ) | |
3 | nn0ge0 12501 | . . . . . 6 ⊢ ((♯‘𝐴) ∈ ℕ0 → 0 ≤ (♯‘𝐴)) | |
4 | ne0gt0 11323 | . . . . . 6 ⊢ (((♯‘𝐴) ∈ ℝ ∧ 0 ≤ (♯‘𝐴)) → ((♯‘𝐴) ≠ 0 ↔ 0 < (♯‘𝐴))) | |
5 | 2, 3, 4 | syl2anc 583 | . . . . 5 ⊢ ((♯‘𝐴) ∈ ℕ0 → ((♯‘𝐴) ≠ 0 ↔ 0 < (♯‘𝐴))) |
6 | 5 | bicomd 222 | . . . 4 ⊢ ((♯‘𝐴) ∈ ℕ0 → (0 < (♯‘𝐴) ↔ (♯‘𝐴) ≠ 0)) |
7 | breq2 5145 | . . . . 5 ⊢ ((♯‘𝐴) = +∞ → (0 < (♯‘𝐴) ↔ 0 < +∞)) | |
8 | 0ltpnf 13108 | . . . . . . 7 ⊢ 0 < +∞ | |
9 | 0re 11220 | . . . . . . . . 9 ⊢ 0 ∈ ℝ | |
10 | renepnf 11266 | . . . . . . . . 9 ⊢ (0 ∈ ℝ → 0 ≠ +∞) | |
11 | 9, 10 | ax-mp 5 | . . . . . . . 8 ⊢ 0 ≠ +∞ |
12 | 11 | necomi 2989 | . . . . . . 7 ⊢ +∞ ≠ 0 |
13 | 8, 12 | 2th 264 | . . . . . 6 ⊢ (0 < +∞ ↔ +∞ ≠ 0) |
14 | neeq1 2997 | . . . . . 6 ⊢ ((♯‘𝐴) = +∞ → ((♯‘𝐴) ≠ 0 ↔ +∞ ≠ 0)) | |
15 | 13, 14 | bitr4id 290 | . . . . 5 ⊢ ((♯‘𝐴) = +∞ → (0 < +∞ ↔ (♯‘𝐴) ≠ 0)) |
16 | 7, 15 | bitrd 279 | . . . 4 ⊢ ((♯‘𝐴) = +∞ → (0 < (♯‘𝐴) ↔ (♯‘𝐴) ≠ 0)) |
17 | 6, 16 | jaoi 854 | . . 3 ⊢ (((♯‘𝐴) ∈ ℕ0 ∨ (♯‘𝐴) = +∞) → (0 < (♯‘𝐴) ↔ (♯‘𝐴) ≠ 0)) |
18 | 1, 17 | syl 17 | . 2 ⊢ (𝐴 ∈ 𝑉 → (0 < (♯‘𝐴) ↔ (♯‘𝐴) ≠ 0)) |
19 | hasheq0 14328 | . . 3 ⊢ (𝐴 ∈ 𝑉 → ((♯‘𝐴) = 0 ↔ 𝐴 = ∅)) | |
20 | 19 | necon3bid 2979 | . 2 ⊢ (𝐴 ∈ 𝑉 → ((♯‘𝐴) ≠ 0 ↔ 𝐴 ≠ ∅)) |
21 | 18, 20 | bitrd 279 | 1 ⊢ (𝐴 ∈ 𝑉 → (0 < (♯‘𝐴) ↔ 𝐴 ≠ ∅)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 205 ∨ wo 844 = wceq 1533 ∈ wcel 2098 ≠ wne 2934 ∅c0 4317 class class class wbr 5141 ‘cfv 6537 ℝcr 11111 0cc0 11112 +∞cpnf 11249 < clt 11252 ≤ cle 11253 ℕ0cn0 12476 ♯chash 14295 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-10 2129 ax-11 2146 ax-12 2163 ax-ext 2697 ax-sep 5292 ax-nul 5299 ax-pow 5356 ax-pr 5420 ax-un 7722 ax-cnex 11168 ax-resscn 11169 ax-1cn 11170 ax-icn 11171 ax-addcl 11172 ax-addrcl 11173 ax-mulcl 11174 ax-mulrcl 11175 ax-mulcom 11176 ax-addass 11177 ax-mulass 11178 ax-distr 11179 ax-i2m1 11180 ax-1ne0 11181 ax-1rid 11182 ax-rnegex 11183 ax-rrecex 11184 ax-cnre 11185 ax-pre-lttri 11186 ax-pre-lttrn 11187 ax-pre-ltadd 11188 ax-pre-mulgt0 11189 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 845 df-3or 1085 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-nf 1778 df-sb 2060 df-mo 2528 df-eu 2557 df-clab 2704 df-cleq 2718 df-clel 2804 df-nfc 2879 df-ne 2935 df-nel 3041 df-ral 3056 df-rex 3065 df-reu 3371 df-rab 3427 df-v 3470 df-sbc 3773 df-csb 3889 df-dif 3946 df-un 3948 df-in 3950 df-ss 3960 df-pss 3962 df-nul 4318 df-if 4524 df-pw 4599 df-sn 4624 df-pr 4626 df-op 4630 df-uni 4903 df-int 4944 df-iun 4992 df-br 5142 df-opab 5204 df-mpt 5225 df-tr 5259 df-id 5567 df-eprel 5573 df-po 5581 df-so 5582 df-fr 5624 df-we 5626 df-xp 5675 df-rel 5676 df-cnv 5677 df-co 5678 df-dm 5679 df-rn 5680 df-res 5681 df-ima 5682 df-pred 6294 df-ord 6361 df-on 6362 df-lim 6363 df-suc 6364 df-iota 6489 df-fun 6539 df-fn 6540 df-f 6541 df-f1 6542 df-fo 6543 df-f1o 6544 df-fv 6545 df-riota 7361 df-ov 7408 df-oprab 7409 df-mpo 7410 df-om 7853 df-1st 7974 df-2nd 7975 df-frecs 8267 df-wrecs 8298 df-recs 8372 df-rdg 8411 df-1o 8467 df-er 8705 df-en 8942 df-dom 8943 df-sdom 8944 df-fin 8945 df-card 9936 df-pnf 11254 df-mnf 11255 df-xr 11256 df-ltxr 11257 df-le 11258 df-sub 11450 df-neg 11451 df-nn 12217 df-n0 12477 df-xnn0 12549 df-z 12563 df-uz 12827 df-fz 13491 df-hash 14296 |
This theorem is referenced by: hashgt0n0 14330 wrdlenge1n0 14506 ccatws1n0 14588 swrdlsw 14623 pfxsuff1eqwrdeq 14655 ccats1pfxeq 14670 wwlksnextinj 29662 clwwlkext2edg 29818 wwlksext2clwwlk 29819 numclwwlk2lem1lem 30104 tgoldbachgt 34204 lfuhgr2 34637 |
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