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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 520 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → 𝐵 ∈ 𝑊) | |
2 | snfig 6759 | . . . . . 6 ⊢ (𝐴 ∈ 𝑉 → {𝐴} ∈ Fin) | |
3 | 2 | ad2antrr 480 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → {𝐴} ∈ Fin) |
4 | elsni 3578 | . . . . . . . 8 ⊢ (𝐵 ∈ {𝐴} → 𝐵 = 𝐴) | |
5 | 4 | eqcomd 2163 | . . . . . . 7 ⊢ (𝐵 ∈ {𝐴} → 𝐴 = 𝐵) |
6 | 5 | necon3ai 2376 | . . . . . 6 ⊢ (𝐴 ≠ 𝐵 → ¬ 𝐵 ∈ {𝐴}) |
7 | 6 | adantl 275 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → ¬ 𝐵 ∈ {𝐴}) |
8 | hashunsng 10681 | . . . . . 6 ⊢ (𝐵 ∈ 𝑊 → (({𝐴} ∈ Fin ∧ ¬ 𝐵 ∈ {𝐴}) → (♯‘({𝐴} ∪ {𝐵})) = ((♯‘{𝐴}) + 1))) | |
9 | 8 | imp 123 | . . . . 5 ⊢ ((𝐵 ∈ 𝑊 ∧ ({𝐴} ∈ Fin ∧ ¬ 𝐵 ∈ {𝐴})) → (♯‘({𝐴} ∪ {𝐵})) = ((♯‘{𝐴}) + 1)) |
10 | 1, 3, 7, 9 | syl12anc 1218 | . . . 4 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘({𝐴} ∪ {𝐵})) = ((♯‘{𝐴}) + 1)) |
11 | hashsng 10672 | . . . . . . 7 ⊢ (𝐴 ∈ 𝑉 → (♯‘{𝐴}) = 1) | |
12 | 11 | adantr 274 | . . . . . 6 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (♯‘{𝐴}) = 1) |
13 | 12 | adantr 274 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘{𝐴}) = 1) |
14 | 13 | oveq1d 5839 | . . . 4 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → ((♯‘{𝐴}) + 1) = (1 + 1)) |
15 | 10, 14 | eqtrd 2190 | . . 3 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘({𝐴} ∪ {𝐵})) = (1 + 1)) |
16 | df-pr 3567 | . . . 4 ⊢ {𝐴, 𝐵} = ({𝐴} ∪ {𝐵}) | |
17 | 16 | fveq2i 5471 | . . 3 ⊢ (♯‘{𝐴, 𝐵}) = (♯‘({𝐴} ∪ {𝐵})) |
18 | df-2 8892 | . . 3 ⊢ 2 = (1 + 1) | |
19 | 15, 17, 18 | 3eqtr4g 2215 | . 2 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘{𝐴, 𝐵}) = 2) |
20 | 1ne2 9039 | . . . . . . 7 ⊢ 1 ≠ 2 | |
21 | 20 | a1i 9 | . . . . . 6 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → 1 ≠ 2) |
22 | 12, 21 | eqnetrd 2351 | . . . . 5 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (♯‘{𝐴}) ≠ 2) |
23 | dfsn2 3574 | . . . . . . . 8 ⊢ {𝐴} = {𝐴, 𝐴} | |
24 | preq2 3637 | . . . . . . . 8 ⊢ (𝐴 = 𝐵 → {𝐴, 𝐴} = {𝐴, 𝐵}) | |
25 | 23, 24 | eqtr2id 2203 | . . . . . . 7 ⊢ (𝐴 = 𝐵 → {𝐴, 𝐵} = {𝐴}) |
26 | 25 | fveq2d 5472 | . . . . . 6 ⊢ (𝐴 = 𝐵 → (♯‘{𝐴, 𝐵}) = (♯‘{𝐴})) |
27 | 26 | neeq1d 2345 | . . . . 5 ⊢ (𝐴 = 𝐵 → ((♯‘{𝐴, 𝐵}) ≠ 2 ↔ (♯‘{𝐴}) ≠ 2)) |
28 | 22, 27 | syl5ibrcom 156 | . . . 4 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 = 𝐵 → (♯‘{𝐴, 𝐵}) ≠ 2)) |
29 | 28 | necon2d 2386 | . . 3 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → ((♯‘{𝐴, 𝐵}) = 2 → 𝐴 ≠ 𝐵)) |
30 | 29 | imp 123 | . 2 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ (♯‘{𝐴, 𝐵}) = 2) → 𝐴 ≠ 𝐵) |
31 | 19, 30 | impbida 586 | 1 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 ≠ 𝐵 ↔ (♯‘{𝐴, 𝐵}) = 2)) |
Colors of variables: wff set class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 103 ↔ wb 104 = wceq 1335 ∈ wcel 2128 ≠ wne 2327 ∪ cun 3100 {csn 3560 {cpr 3561 ‘cfv 5170 (class class class)co 5824 Fincfn 6685 1c1 7733 + caddc 7735 2c2 8884 ♯chash 10649 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 105 ax-ia2 106 ax-ia3 107 ax-in1 604 ax-in2 605 ax-io 699 ax-5 1427 ax-7 1428 ax-gen 1429 ax-ie1 1473 ax-ie2 1474 ax-8 1484 ax-10 1485 ax-11 1486 ax-i12 1487 ax-bndl 1489 ax-4 1490 ax-17 1506 ax-i9 1510 ax-ial 1514 ax-i5r 1515 ax-13 2130 ax-14 2131 ax-ext 2139 ax-coll 4079 ax-sep 4082 ax-nul 4090 ax-pow 4135 ax-pr 4169 ax-un 4393 ax-setind 4496 ax-iinf 4547 ax-cnex 7823 ax-resscn 7824 ax-1cn 7825 ax-1re 7826 ax-icn 7827 ax-addcl 7828 ax-addrcl 7829 ax-mulcl 7830 ax-addcom 7832 ax-addass 7834 ax-distr 7836 ax-i2m1 7837 ax-0lt1 7838 ax-0id 7840 ax-rnegex 7841 ax-cnre 7843 ax-pre-ltirr 7844 ax-pre-ltwlin 7845 ax-pre-lttrn 7846 ax-pre-apti 7847 ax-pre-ltadd 7848 |
This theorem depends on definitions: df-bi 116 df-dc 821 df-3or 964 df-3an 965 df-tru 1338 df-fal 1341 df-nf 1441 df-sb 1743 df-eu 2009 df-mo 2010 df-clab 2144 df-cleq 2150 df-clel 2153 df-nfc 2288 df-ne 2328 df-nel 2423 df-ral 2440 df-rex 2441 df-reu 2442 df-rab 2444 df-v 2714 df-sbc 2938 df-csb 3032 df-dif 3104 df-un 3106 df-in 3108 df-ss 3115 df-nul 3395 df-if 3506 df-pw 3545 df-sn 3566 df-pr 3567 df-op 3569 df-uni 3773 df-int 3808 df-iun 3851 df-br 3966 df-opab 4026 df-mpt 4027 df-tr 4063 df-id 4253 df-iord 4326 df-on 4328 df-ilim 4329 df-suc 4331 df-iom 4550 df-xp 4592 df-rel 4593 df-cnv 4594 df-co 4595 df-dm 4596 df-rn 4597 df-res 4598 df-ima 4599 df-iota 5135 df-fun 5172 df-fn 5173 df-f 5174 df-f1 5175 df-fo 5176 df-f1o 5177 df-fv 5178 df-riota 5780 df-ov 5827 df-oprab 5828 df-mpo 5829 df-1st 6088 df-2nd 6089 df-recs 6252 df-irdg 6317 df-frec 6338 df-1o 6363 df-oadd 6367 df-er 6480 df-en 6686 df-dom 6687 df-fin 6688 df-pnf 7914 df-mnf 7915 df-xr 7916 df-ltxr 7917 df-le 7918 df-sub 8048 df-neg 8049 df-inn 8834 df-2 8892 df-n0 9091 df-z 9168 df-uz 9440 df-fz 9913 df-ihash 10650 |
This theorem is referenced by: prhash2ex 10683 fiprsshashgt1 10691 |
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