Description: The difference of two even numbers is even. (Contributed by AV, 21-Jul-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | emee | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | evenz | |
|
2 | 1 | zcnd | |
3 | evenz | |
|
4 | 3 | zcnd | |
5 | negsub | |
|
6 | 2 4 5 | syl2an | |
7 | enege | |
|
8 | epee | |
|
9 | 7 8 | sylan2 | |
10 | 6 9 | eqeltrrd | |