Description: The upper integers starting from a natural are a subset of the naturals. (Contributed by Scott Fenton, 29-Jun-2013)
Ref | Expression | ||
---|---|---|---|
Assertion | uznnssnn | |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | elnnuz | |
|
2 | uzss | |
|
3 | 1 2 | sylbi | |
4 | nnuz | |
|
5 | 3 4 | sseqtrrdi | |