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Related theorems GIF version |
| Description: The empty set is a relation. |
| Ref | Expression |
|---|---|
| rel0 | ⊢ Rel ∅ |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0ss 1725 | . 2 ⊢ ∅ ⊆ (V × V) | |
| 2 | df-rel 2425 | . 2 ⊢ (Rel ∅ ↔ ∅ ⊆ (V × V)) | |
| 3 | 1, 2 | mpbir 165 | 1 ⊢ Rel ∅ |
| Colors of variables: wff set class |
| Syntax hints: Vcvv 1348 ⊆ wss 1487 ∅c0 1707 × cxp 2408 Rel wrel 2415 |
| This theorem is referenced by: reldm0 2550 intirr 2628 cnv0 2633 co02 2663 co01 2664 fn0 2739 |
| This theorem was proved from axioms: ax-1 3 ax-2 4 ax-3 5 ax-mp 6 ax-4 673 ax-5 674 ax-6 675 ax-7 676 ax-gen 677 ax-8 798 ax-9 799 ax-10 800 ax-11 801 ax-12 802 ax-16 922 ax-17 925 ax-ext 1074 |
| This theorem depends on definitions: df-bi 128 df-or 197 df-an 198 df-ex 679 df-sb 853 df-clab 1093 df-cleq 1097 df-clel 1099 df-v 1349 df-dif 1489 df-in 1491 df-ss 1492 df-nul 1708 df-rel 2425 |