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Mirrors > Home > MPE Home > Th. List > en2eqpr | Structured version Visualization version GIF version |
Description: Building a set with two elements. (Contributed by FL, 11-Aug-2008.) (Revised by Mario Carneiro, 10-Sep-2015.) |
Ref | Expression |
---|---|
en2eqpr | ⊢ ((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) → (𝐴 ≠ 𝐵 → 𝐶 = {𝐴, 𝐵})) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 2onn 8664 | . . . . . 6 ⊢ 2o ∈ ω | |
2 | nnfi 9197 | . . . . . 6 ⊢ (2o ∈ ω → 2o ∈ Fin) | |
3 | 1, 2 | ax-mp 5 | . . . . 5 ⊢ 2o ∈ Fin |
4 | simpl1 1188 | . . . . 5 ⊢ (((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → 𝐶 ≈ 2o) | |
5 | enfii 9216 | . . . . 5 ⊢ ((2o ∈ Fin ∧ 𝐶 ≈ 2o) → 𝐶 ∈ Fin) | |
6 | 3, 4, 5 | sylancr 585 | . . . 4 ⊢ (((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → 𝐶 ∈ Fin) |
7 | simpl2 1189 | . . . . 5 ⊢ (((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → 𝐴 ∈ 𝐶) | |
8 | simpl3 1190 | . . . . 5 ⊢ (((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → 𝐵 ∈ 𝐶) | |
9 | 7, 8 | prssd 4821 | . . . 4 ⊢ (((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → {𝐴, 𝐵} ⊆ 𝐶) |
10 | enpr2 10038 | . . . . . . 7 ⊢ ((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶 ∧ 𝐴 ≠ 𝐵) → {𝐴, 𝐵} ≈ 2o) | |
11 | 10 | 3expa 1115 | . . . . . 6 ⊢ (((𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → {𝐴, 𝐵} ≈ 2o) |
12 | 11 | 3adantl1 1163 | . . . . 5 ⊢ (((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → {𝐴, 𝐵} ≈ 2o) |
13 | 4 | ensymd 9028 | . . . . 5 ⊢ (((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → 2o ≈ 𝐶) |
14 | entr 9029 | . . . . 5 ⊢ (({𝐴, 𝐵} ≈ 2o ∧ 2o ≈ 𝐶) → {𝐴, 𝐵} ≈ 𝐶) | |
15 | 12, 13, 14 | syl2anc 582 | . . . 4 ⊢ (((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → {𝐴, 𝐵} ≈ 𝐶) |
16 | fisseneq 9284 | . . . 4 ⊢ ((𝐶 ∈ Fin ∧ {𝐴, 𝐵} ⊆ 𝐶 ∧ {𝐴, 𝐵} ≈ 𝐶) → {𝐴, 𝐵} = 𝐶) | |
17 | 6, 9, 15, 16 | syl3anc 1368 | . . 3 ⊢ (((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → {𝐴, 𝐵} = 𝐶) |
18 | 17 | eqcomd 2732 | . 2 ⊢ (((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) ∧ 𝐴 ≠ 𝐵) → 𝐶 = {𝐴, 𝐵}) |
19 | 18 | ex 411 | 1 ⊢ ((𝐶 ≈ 2o ∧ 𝐴 ∈ 𝐶 ∧ 𝐵 ∈ 𝐶) → (𝐴 ≠ 𝐵 → 𝐶 = {𝐴, 𝐵})) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 394 ∧ w3a 1084 = wceq 1534 ∈ wcel 2099 ≠ wne 2930 ⊆ wss 3946 {cpr 4625 class class class wbr 5145 ωcom 7868 2oc2o 8482 ≈ cen 8963 Fincfn 8966 |
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-sep 5296 ax-nul 5303 ax-pow 5361 ax-pr 5425 ax-un 7738 |
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-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-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-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-om 7869 df-1o 8488 df-2o 8489 df-er 8726 df-en 8967 df-dom 8968 df-sdom 8969 df-fin 8970 |
This theorem is referenced by: isprm2lem 16677 en2top 22976 |
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