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