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| Mirrors > Home > ILE Home > Th. List > brne0 | GIF version | ||
| Description: If two sets are in a binary relation, the relation cannot be empty. In fact, the relation is also inhabited, as seen at brm 4139. (Contributed by Alexander van der Vekens, 7-Jul-2018.) |
| Ref | Expression |
|---|---|
| brne0 | ⊢ (𝐴𝑅𝐵 → 𝑅 ≠ ∅) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-br 4089 | . 2 ⊢ (𝐴𝑅𝐵 ↔ 〈𝐴, 𝐵〉 ∈ 𝑅) | |
| 2 | ne0i 3501 | . 2 ⊢ (〈𝐴, 𝐵〉 ∈ 𝑅 → 𝑅 ≠ ∅) | |
| 3 | 1, 2 | sylbi 121 | 1 ⊢ (𝐴𝑅𝐵 → 𝑅 ≠ ∅) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ∈ wcel 2202 ≠ wne 2402 ∅c0 3494 〈cop 3672 class class class wbr 4088 |
| 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 619 ax-in2 620 ax-io 716 ax-5 1495 ax-7 1496 ax-gen 1497 ax-ie1 1541 ax-ie2 1542 ax-8 1552 ax-10 1553 ax-11 1554 ax-i12 1555 ax-bndl 1557 ax-4 1558 ax-17 1574 ax-i9 1578 ax-ial 1582 ax-i5r 1583 ax-ext 2213 |
| This theorem depends on definitions: df-bi 117 df-tru 1400 df-nf 1509 df-sb 1811 df-clab 2218 df-cleq 2224 df-clel 2227 df-nfc 2363 df-ne 2403 df-v 2804 df-dif 3202 df-nul 3495 df-br 4089 |
| This theorem is referenced by: (None) |
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