Description: The integers form a subring of the complex numbers. (Contributed by Mario Carneiro, 4-Dec-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | zsubrg | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | zcn | |
|
2 | zaddcl | |
|
3 | znegcl | |
|
4 | 1z | |
|
5 | zmulcl | |
|
6 | 1 2 3 4 5 | cnsubrglem | |