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Mirrors > Home > ILE Home > Th. List > tpid2 | GIF version |
Description: One of the three elements of an unordered triple. (Contributed by NM, 7-Apr-1994.) (Proof shortened by Andrew Salmon, 29-Jun-2011.) |
Ref | Expression |
---|---|
tpid2.1 | ⊢ 𝐵 ∈ V |
Ref | Expression |
---|---|
tpid2 | ⊢ 𝐵 ∈ {𝐴, 𝐵, 𝐶} |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqid 2177 | . . 3 ⊢ 𝐵 = 𝐵 | |
2 | 1 | 3mix2i 1170 | . 2 ⊢ (𝐵 = 𝐴 ∨ 𝐵 = 𝐵 ∨ 𝐵 = 𝐶) |
3 | tpid2.1 | . . 3 ⊢ 𝐵 ∈ V | |
4 | 3 | eltp 3640 | . 2 ⊢ (𝐵 ∈ {𝐴, 𝐵, 𝐶} ↔ (𝐵 = 𝐴 ∨ 𝐵 = 𝐵 ∨ 𝐵 = 𝐶)) |
5 | 2, 4 | mpbir 146 | 1 ⊢ 𝐵 ∈ {𝐴, 𝐵, 𝐶} |
Colors of variables: wff set class |
Syntax hints: ∨ w3o 977 = wceq 1353 ∈ wcel 2148 Vcvv 2737 {ctp 3594 |
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-io 709 ax-5 1447 ax-7 1448 ax-gen 1449 ax-ie1 1493 ax-ie2 1494 ax-8 1504 ax-10 1505 ax-11 1506 ax-i12 1507 ax-bndl 1509 ax-4 1510 ax-17 1526 ax-i9 1530 ax-ial 1534 ax-i5r 1535 ax-ext 2159 |
This theorem depends on definitions: df-bi 117 df-3or 979 df-tru 1356 df-nf 1461 df-sb 1763 df-clab 2164 df-cleq 2170 df-clel 2173 df-nfc 2308 df-v 2739 df-un 3133 df-sn 3598 df-pr 3599 df-tp 3600 |
This theorem is referenced by: (None) |
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