Description: An even number is an integer. (Contributed by AV, 14-Jun-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | evenz | |- ( Z e. Even -> Z e. ZZ ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | iseven | |- ( Z e. Even <-> ( Z e. ZZ /\ ( Z / 2 ) e. ZZ ) ) |
|
2 | 1 | simplbi | |- ( Z e. Even -> Z e. ZZ ) |