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Related theorems Unicode version |
| Description: The empty set is a relation. |
| Ref | Expression |
|---|---|
| rel0 |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0ss 2291 |
. 2
| |
| 2 | df-rel 3175 |
. 2
| |
| 3 | 1, 2 | mpbir 190 |
1
|
| Colors of variables: wff set class |
| Syntax hints: |
| This theorem is referenced by: reldm0 3320 intirr 3427 cnv0 3432 co02 3494 co01 3495 fn0 3591 |
| This theorem was proved from axioms: ax-1 4 ax-2 5 ax-3 6 ax-mp 7 ax-7 959 ax-gen 960 ax-8 961 ax-10 963 ax-12 965 ax-17 968 ax-4 970 ax-5o 972 ax-6o 975 ax-9o 1119 ax-10o 1136 ax-16 1206 ax-11o 1213 ax-ext 1452 |
| This theorem depends on definitions: df-bi 147 df-or 224 df-an 225 df-ex 978 df-sb 1168 df-clab 1457 df-cleq 1462 df-clel 1465 df-v 1803 df-dif 2039 df-in 2041 df-ss 2043 df-nul 2271 df-rel 3175 |