Metamath Proof Explorer
Description: The cardinality of a set is greater than or equal to zero. (Contributed by Thierry Arnoux, 2-Mar-2017)
|
|
Ref |
Expression |
|
Assertion |
hashge0 |
|
Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
|
0domg |
|
| 2 |
|
hashdomi |
|
| 3 |
|
hash0 |
|
| 4 |
3
|
breq1i |
|
| 5 |
4
|
biimpi |
|
| 6 |
1 2 5
|
3syl |
|