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| Mirrors > Home > NFE Home > Th. List > df-0c | Unicode version | ||
| Description: Define cardinal zero. (Contributed by SF, 12-Jan-2015.) |
| Ref | Expression |
|---|---|
| df-0c |
|
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | c0c 4375 |
. 2
| |
| 2 | c0 3551 |
. . 3
| |
| 3 | 2 | csn 3738 |
. 2
|
| 4 | 1, 3 | wceq 1642 |
1
|
| Colors of variables: wff setvar class |
| This definition is referenced by: 0cex 4393 0cnsuc 4402 addcid1 4406 el0c 4422 nnsucelr 4429 nndisjeq 4430 ssfin 4471 0ceven 4506 lec0cg 6199 |
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