Metamath Proof Explorer


Theorem zsubrg

Description: The integers form a subring of the complex numbers. (Contributed by Mario Carneiro, 4-Dec-2014)

Ref Expression
Assertion zsubrg SubRingfld

Proof

Step Hyp Ref Expression
1 zcn xx
2 zaddcl xyx+y
3 znegcl xx
4 1z 1
5 zmulcl xyxy
6 1 2 3 4 5 cnsubrglem SubRingfld