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Mirrors > Home > ILE Home > Th. List > hashprg | GIF version |
Description: The size of an unordered pair. (Contributed by Mario Carneiro, 27-Sep-2013.) (Revised by Mario Carneiro, 5-May-2016.) (Revised by AV, 18-Sep-2021.) |
Ref | Expression |
---|---|
hashprg | ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 ≠ 𝐵 ↔ (♯‘{𝐴, 𝐵}) = 2)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simplr 497 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → 𝐵 ∈ 𝑊) | |
2 | snfig 6459 | . . . . . 6 ⊢ (𝐴 ∈ 𝑉 → {𝐴} ∈ Fin) | |
3 | 2 | ad2antrr 472 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → {𝐴} ∈ Fin) |
4 | elsni 3440 | . . . . . . . 8 ⊢ (𝐵 ∈ {𝐴} → 𝐵 = 𝐴) | |
5 | 4 | eqcomd 2088 | . . . . . . 7 ⊢ (𝐵 ∈ {𝐴} → 𝐴 = 𝐵) |
6 | 5 | necon3ai 2298 | . . . . . 6 ⊢ (𝐴 ≠ 𝐵 → ¬ 𝐵 ∈ {𝐴}) |
7 | 6 | adantl 271 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → ¬ 𝐵 ∈ {𝐴}) |
8 | hashunsng 10048 | . . . . . 6 ⊢ (𝐵 ∈ 𝑊 → (({𝐴} ∈ Fin ∧ ¬ 𝐵 ∈ {𝐴}) → (♯‘({𝐴} ∪ {𝐵})) = ((♯‘{𝐴}) + 1))) | |
9 | 8 | imp 122 | . . . . 5 ⊢ ((𝐵 ∈ 𝑊 ∧ ({𝐴} ∈ Fin ∧ ¬ 𝐵 ∈ {𝐴})) → (♯‘({𝐴} ∪ {𝐵})) = ((♯‘{𝐴}) + 1)) |
10 | 1, 3, 7, 9 | syl12anc 1168 | . . . 4 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘({𝐴} ∪ {𝐵})) = ((♯‘{𝐴}) + 1)) |
11 | hashsng 10039 | . . . . . . 7 ⊢ (𝐴 ∈ 𝑉 → (♯‘{𝐴}) = 1) | |
12 | 11 | adantr 270 | . . . . . 6 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (♯‘{𝐴}) = 1) |
13 | 12 | adantr 270 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘{𝐴}) = 1) |
14 | 13 | oveq1d 5604 | . . . 4 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → ((♯‘{𝐴}) + 1) = (1 + 1)) |
15 | 10, 14 | eqtrd 2115 | . . 3 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘({𝐴} ∪ {𝐵})) = (1 + 1)) |
16 | df-pr 3429 | . . . 4 ⊢ {𝐴, 𝐵} = ({𝐴} ∪ {𝐵}) | |
17 | 16 | fveq2i 5254 | . . 3 ⊢ (♯‘{𝐴, 𝐵}) = (♯‘({𝐴} ∪ {𝐵})) |
18 | df-2 8373 | . . 3 ⊢ 2 = (1 + 1) | |
19 | 15, 17, 18 | 3eqtr4g 2140 | . 2 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘{𝐴, 𝐵}) = 2) |
20 | 1ne2 8513 | . . . . . . 7 ⊢ 1 ≠ 2 | |
21 | 20 | a1i 9 | . . . . . 6 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → 1 ≠ 2) |
22 | 12, 21 | eqnetrd 2273 | . . . . 5 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (♯‘{𝐴}) ≠ 2) |
23 | dfsn2 3436 | . . . . . . . 8 ⊢ {𝐴} = {𝐴, 𝐴} | |
24 | preq2 3494 | . . . . . . . 8 ⊢ (𝐴 = 𝐵 → {𝐴, 𝐴} = {𝐴, 𝐵}) | |
25 | 23, 24 | syl5req 2128 | . . . . . . 7 ⊢ (𝐴 = 𝐵 → {𝐴, 𝐵} = {𝐴}) |
26 | 25 | fveq2d 5255 | . . . . . 6 ⊢ (𝐴 = 𝐵 → (♯‘{𝐴, 𝐵}) = (♯‘{𝐴})) |
27 | 26 | neeq1d 2267 | . . . . 5 ⊢ (𝐴 = 𝐵 → ((♯‘{𝐴, 𝐵}) ≠ 2 ↔ (♯‘{𝐴}) ≠ 2)) |
28 | 22, 27 | syl5ibrcom 155 | . . . 4 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 = 𝐵 → (♯‘{𝐴, 𝐵}) ≠ 2)) |
29 | 28 | necon2d 2308 | . . 3 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → ((♯‘{𝐴, 𝐵}) = 2 → 𝐴 ≠ 𝐵)) |
30 | 29 | imp 122 | . 2 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ (♯‘{𝐴, 𝐵}) = 2) → 𝐴 ≠ 𝐵) |
31 | 19, 30 | impbida 561 | 1 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 ≠ 𝐵 ↔ (♯‘{𝐴, 𝐵}) = 2)) |
Colors of variables: wff set class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 102 ↔ wb 103 = wceq 1285 ∈ wcel 1434 ≠ wne 2249 ∪ cun 2982 {csn 3422 {cpr 3423 ‘cfv 4967 (class class class)co 5589 Fincfn 6385 1c1 7252 + caddc 7254 2c2 8364 ♯chash 10016 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-in1 577 ax-in2 578 ax-io 663 ax-5 1377 ax-7 1378 ax-gen 1379 ax-ie1 1423 ax-ie2 1424 ax-8 1436 ax-10 1437 ax-11 1438 ax-i12 1439 ax-bndl 1440 ax-4 1441 ax-13 1445 ax-14 1446 ax-17 1460 ax-i9 1464 ax-ial 1468 ax-i5r 1469 ax-ext 2065 ax-coll 3919 ax-sep 3922 ax-nul 3930 ax-pow 3974 ax-pr 3999 ax-un 4223 ax-setind 4315 ax-iinf 4365 ax-cnex 7337 ax-resscn 7338 ax-1cn 7339 ax-1re 7340 ax-icn 7341 ax-addcl 7342 ax-addrcl 7343 ax-mulcl 7344 ax-addcom 7346 ax-addass 7348 ax-distr 7350 ax-i2m1 7351 ax-0lt1 7352 ax-0id 7354 ax-rnegex 7355 ax-cnre 7357 ax-pre-ltirr 7358 ax-pre-ltwlin 7359 ax-pre-lttrn 7360 ax-pre-apti 7361 ax-pre-ltadd 7362 |
This theorem depends on definitions: df-bi 115 df-dc 777 df-3or 921 df-3an 922 df-tru 1288 df-fal 1291 df-nf 1391 df-sb 1688 df-eu 1946 df-mo 1947 df-clab 2070 df-cleq 2076 df-clel 2079 df-nfc 2212 df-ne 2250 df-nel 2345 df-ral 2358 df-rex 2359 df-reu 2360 df-rab 2362 df-v 2614 df-sbc 2827 df-csb 2920 df-dif 2986 df-un 2988 df-in 2990 df-ss 2997 df-nul 3270 df-if 3374 df-pw 3408 df-sn 3428 df-pr 3429 df-op 3431 df-uni 3628 df-int 3663 df-iun 3706 df-br 3812 df-opab 3866 df-mpt 3867 df-tr 3902 df-id 4083 df-iord 4156 df-on 4158 df-ilim 4159 df-suc 4161 df-iom 4368 df-xp 4405 df-rel 4406 df-cnv 4407 df-co 4408 df-dm 4409 df-rn 4410 df-res 4411 df-ima 4412 df-iota 4932 df-fun 4969 df-fn 4970 df-f 4971 df-f1 4972 df-fo 4973 df-f1o 4974 df-fv 4975 df-riota 5545 df-ov 5592 df-oprab 5593 df-mpt2 5594 df-1st 5844 df-2nd 5845 df-recs 6000 df-irdg 6065 df-frec 6086 df-1o 6111 df-oadd 6115 df-er 6220 df-en 6386 df-dom 6387 df-fin 6388 df-pnf 7425 df-mnf 7426 df-xr 7427 df-ltxr 7428 df-le 7429 df-sub 7556 df-neg 7557 df-inn 8315 df-2 8373 df-n0 8564 df-z 8645 df-uz 8913 df-fz 9318 df-ihash 10017 |
This theorem is referenced by: prhash2ex 10050 fiprsshashgt1 10058 |
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