Description: 2 divides 4. That means 4 is even. (Contributed by AV, 23-Jul-2020) (Revised by AV, 4-Jul-2021)
Ref | Expression | ||
---|---|---|---|
Assertion | z4even | |- 2 || 4 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 2z | |- 2 e. ZZ |
|
2 | dvdsmul1 | |- ( ( 2 e. ZZ /\ 2 e. ZZ ) -> 2 || ( 2 x. 2 ) ) |
|
3 | 1 1 2 | mp2an | |- 2 || ( 2 x. 2 ) |
4 | 2t2e4 | |- ( 2 x. 2 ) = 4 |
|
5 | 3 4 | breqtri | |- 2 || 4 |