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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 528 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → 𝐵 ∈ 𝑊) | |
2 | snfig 6828 | . . . . . 6 ⊢ (𝐴 ∈ 𝑉 → {𝐴} ∈ Fin) | |
3 | 2 | ad2antrr 488 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → {𝐴} ∈ Fin) |
4 | elsni 3622 | . . . . . . . 8 ⊢ (𝐵 ∈ {𝐴} → 𝐵 = 𝐴) | |
5 | 4 | eqcomd 2193 | . . . . . . 7 ⊢ (𝐵 ∈ {𝐴} → 𝐴 = 𝐵) |
6 | 5 | necon3ai 2406 | . . . . . 6 ⊢ (𝐴 ≠ 𝐵 → ¬ 𝐵 ∈ {𝐴}) |
7 | 6 | adantl 277 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → ¬ 𝐵 ∈ {𝐴}) |
8 | hashunsng 10801 | . . . . . 6 ⊢ (𝐵 ∈ 𝑊 → (({𝐴} ∈ Fin ∧ ¬ 𝐵 ∈ {𝐴}) → (♯‘({𝐴} ∪ {𝐵})) = ((♯‘{𝐴}) + 1))) | |
9 | 8 | imp 124 | . . . . 5 ⊢ ((𝐵 ∈ 𝑊 ∧ ({𝐴} ∈ Fin ∧ ¬ 𝐵 ∈ {𝐴})) → (♯‘({𝐴} ∪ {𝐵})) = ((♯‘{𝐴}) + 1)) |
10 | 1, 3, 7, 9 | syl12anc 1246 | . . . 4 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘({𝐴} ∪ {𝐵})) = ((♯‘{𝐴}) + 1)) |
11 | hashsng 10792 | . . . . . . 7 ⊢ (𝐴 ∈ 𝑉 → (♯‘{𝐴}) = 1) | |
12 | 11 | adantr 276 | . . . . . 6 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (♯‘{𝐴}) = 1) |
13 | 12 | adantr 276 | . . . . 5 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘{𝐴}) = 1) |
14 | 13 | oveq1d 5903 | . . . 4 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → ((♯‘{𝐴}) + 1) = (1 + 1)) |
15 | 10, 14 | eqtrd 2220 | . . 3 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘({𝐴} ∪ {𝐵})) = (1 + 1)) |
16 | df-pr 3611 | . . . 4 ⊢ {𝐴, 𝐵} = ({𝐴} ∪ {𝐵}) | |
17 | 16 | fveq2i 5530 | . . 3 ⊢ (♯‘{𝐴, 𝐵}) = (♯‘({𝐴} ∪ {𝐵})) |
18 | df-2 8992 | . . 3 ⊢ 2 = (1 + 1) | |
19 | 15, 17, 18 | 3eqtr4g 2245 | . 2 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ 𝐴 ≠ 𝐵) → (♯‘{𝐴, 𝐵}) = 2) |
20 | 1ne2 9139 | . . . . . . 7 ⊢ 1 ≠ 2 | |
21 | 20 | a1i 9 | . . . . . 6 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → 1 ≠ 2) |
22 | 12, 21 | eqnetrd 2381 | . . . . 5 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (♯‘{𝐴}) ≠ 2) |
23 | dfsn2 3618 | . . . . . . . 8 ⊢ {𝐴} = {𝐴, 𝐴} | |
24 | preq2 3682 | . . . . . . . 8 ⊢ (𝐴 = 𝐵 → {𝐴, 𝐴} = {𝐴, 𝐵}) | |
25 | 23, 24 | eqtr2id 2233 | . . . . . . 7 ⊢ (𝐴 = 𝐵 → {𝐴, 𝐵} = {𝐴}) |
26 | 25 | fveq2d 5531 | . . . . . 6 ⊢ (𝐴 = 𝐵 → (♯‘{𝐴, 𝐵}) = (♯‘{𝐴})) |
27 | 26 | neeq1d 2375 | . . . . 5 ⊢ (𝐴 = 𝐵 → ((♯‘{𝐴, 𝐵}) ≠ 2 ↔ (♯‘{𝐴}) ≠ 2)) |
28 | 22, 27 | syl5ibrcom 157 | . . . 4 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 = 𝐵 → (♯‘{𝐴, 𝐵}) ≠ 2)) |
29 | 28 | necon2d 2416 | . . 3 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → ((♯‘{𝐴, 𝐵}) = 2 → 𝐴 ≠ 𝐵)) |
30 | 29 | imp 124 | . 2 ⊢ (((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) ∧ (♯‘{𝐴, 𝐵}) = 2) → 𝐴 ≠ 𝐵) |
31 | 19, 30 | impbida 596 | 1 ⊢ ((𝐴 ∈ 𝑉 ∧ 𝐵 ∈ 𝑊) → (𝐴 ≠ 𝐵 ↔ (♯‘{𝐴, 𝐵}) = 2)) |
Colors of variables: wff set class |
Syntax hints: ¬ wn 3 → wi 4 ∧ wa 104 ↔ wb 105 = wceq 1363 ∈ wcel 2158 ≠ wne 2357 ∪ cun 3139 {csn 3604 {cpr 3605 ‘cfv 5228 (class class class)co 5888 Fincfn 6754 1c1 7826 + caddc 7828 2c2 8984 ♯chash 10769 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in1 615 ax-in2 616 ax-io 710 ax-5 1457 ax-7 1458 ax-gen 1459 ax-ie1 1503 ax-ie2 1504 ax-8 1514 ax-10 1515 ax-11 1516 ax-i12 1517 ax-bndl 1519 ax-4 1520 ax-17 1536 ax-i9 1540 ax-ial 1544 ax-i5r 1545 ax-13 2160 ax-14 2161 ax-ext 2169 ax-coll 4130 ax-sep 4133 ax-nul 4141 ax-pow 4186 ax-pr 4221 ax-un 4445 ax-setind 4548 ax-iinf 4599 ax-cnex 7916 ax-resscn 7917 ax-1cn 7918 ax-1re 7919 ax-icn 7920 ax-addcl 7921 ax-addrcl 7922 ax-mulcl 7923 ax-addcom 7925 ax-addass 7927 ax-distr 7929 ax-i2m1 7930 ax-0lt1 7931 ax-0id 7933 ax-rnegex 7934 ax-cnre 7936 ax-pre-ltirr 7937 ax-pre-ltwlin 7938 ax-pre-lttrn 7939 ax-pre-apti 7940 ax-pre-ltadd 7941 |
This theorem depends on definitions: df-bi 117 df-dc 836 df-3or 980 df-3an 981 df-tru 1366 df-fal 1369 df-nf 1471 df-sb 1773 df-eu 2039 df-mo 2040 df-clab 2174 df-cleq 2180 df-clel 2183 df-nfc 2318 df-ne 2358 df-nel 2453 df-ral 2470 df-rex 2471 df-reu 2472 df-rab 2474 df-v 2751 df-sbc 2975 df-csb 3070 df-dif 3143 df-un 3145 df-in 3147 df-ss 3154 df-nul 3435 df-if 3547 df-pw 3589 df-sn 3610 df-pr 3611 df-op 3613 df-uni 3822 df-int 3857 df-iun 3900 df-br 4016 df-opab 4077 df-mpt 4078 df-tr 4114 df-id 4305 df-iord 4378 df-on 4380 df-ilim 4381 df-suc 4383 df-iom 4602 df-xp 4644 df-rel 4645 df-cnv 4646 df-co 4647 df-dm 4648 df-rn 4649 df-res 4650 df-ima 4651 df-iota 5190 df-fun 5230 df-fn 5231 df-f 5232 df-f1 5233 df-fo 5234 df-f1o 5235 df-fv 5236 df-riota 5844 df-ov 5891 df-oprab 5892 df-mpo 5893 df-1st 6155 df-2nd 6156 df-recs 6320 df-irdg 6385 df-frec 6406 df-1o 6431 df-oadd 6435 df-er 6549 df-en 6755 df-dom 6756 df-fin 6757 df-pnf 8008 df-mnf 8009 df-xr 8010 df-ltxr 8011 df-le 8012 df-sub 8144 df-neg 8145 df-inn 8934 df-2 8992 df-n0 9191 df-z 9268 df-uz 9543 df-fz 10023 df-ihash 10770 |
This theorem is referenced by: prhash2ex 10803 fiprsshashgt1 10811 |
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