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Mirrors > Home > ILE Home > Th. List > eldifpr | GIF version |
Description: Membership in a set with two elements removed. Similar to eldifsn 3682 and eldiftp 3601. (Contributed by Mario Carneiro, 18-Jul-2017.) |
Ref | Expression |
---|---|
eldifpr | ⊢ (𝐴 ∈ (𝐵 ∖ {𝐶, 𝐷}) ↔ (𝐴 ∈ 𝐵 ∧ 𝐴 ≠ 𝐶 ∧ 𝐴 ≠ 𝐷)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elprg 3576 | . . . . 5 ⊢ (𝐴 ∈ 𝐵 → (𝐴 ∈ {𝐶, 𝐷} ↔ (𝐴 = 𝐶 ∨ 𝐴 = 𝐷))) | |
2 | 1 | notbid 657 | . . . 4 ⊢ (𝐴 ∈ 𝐵 → (¬ 𝐴 ∈ {𝐶, 𝐷} ↔ ¬ (𝐴 = 𝐶 ∨ 𝐴 = 𝐷))) |
3 | neanior 2411 | . . . 4 ⊢ ((𝐴 ≠ 𝐶 ∧ 𝐴 ≠ 𝐷) ↔ ¬ (𝐴 = 𝐶 ∨ 𝐴 = 𝐷)) | |
4 | 2, 3 | bitr4di 197 | . . 3 ⊢ (𝐴 ∈ 𝐵 → (¬ 𝐴 ∈ {𝐶, 𝐷} ↔ (𝐴 ≠ 𝐶 ∧ 𝐴 ≠ 𝐷))) |
5 | 4 | pm5.32i 450 | . 2 ⊢ ((𝐴 ∈ 𝐵 ∧ ¬ 𝐴 ∈ {𝐶, 𝐷}) ↔ (𝐴 ∈ 𝐵 ∧ (𝐴 ≠ 𝐶 ∧ 𝐴 ≠ 𝐷))) |
6 | eldif 3107 | . 2 ⊢ (𝐴 ∈ (𝐵 ∖ {𝐶, 𝐷}) ↔ (𝐴 ∈ 𝐵 ∧ ¬ 𝐴 ∈ {𝐶, 𝐷})) | |
7 | 3anass 967 | . 2 ⊢ ((𝐴 ∈ 𝐵 ∧ 𝐴 ≠ 𝐶 ∧ 𝐴 ≠ 𝐷) ↔ (𝐴 ∈ 𝐵 ∧ (𝐴 ≠ 𝐶 ∧ 𝐴 ≠ 𝐷))) | |
8 | 5, 6, 7 | 3bitr4i 211 | 1 ⊢ (𝐴 ∈ (𝐵 ∖ {𝐶, 𝐷}) ↔ (𝐴 ∈ 𝐵 ∧ 𝐴 ≠ 𝐶 ∧ 𝐴 ≠ 𝐷)) |
Colors of variables: wff set class |
Syntax hints: ¬ wn 3 ∧ wa 103 ↔ wb 104 ∨ wo 698 ∧ w3a 963 = wceq 1332 ∈ wcel 2125 ≠ wne 2324 ∖ cdif 3095 {cpr 3557 |
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 1424 ax-7 1425 ax-gen 1426 ax-ie1 1470 ax-ie2 1471 ax-8 1481 ax-10 1482 ax-11 1483 ax-i12 1484 ax-bndl 1486 ax-4 1487 ax-17 1503 ax-i9 1507 ax-ial 1511 ax-i5r 1512 ax-ext 2136 |
This theorem depends on definitions: df-bi 116 df-3an 965 df-tru 1335 df-nf 1438 df-sb 1740 df-clab 2141 df-cleq 2147 df-clel 2150 df-nfc 2285 df-ne 2325 df-v 2711 df-dif 3100 df-un 3102 df-sn 3562 df-pr 3563 |
This theorem is referenced by: rexdifpr 3584 rplogbval 13201 |
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