This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.
Metamath Proof Explorer
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 |
|
Proof
| Step |
Hyp |
Ref |
Expression |
| 1 |
|
elnnuz |
|
| 2 |
|
uzss |
|
| 3 |
1 2
|
sylbi |
|
| 4 |
|
nnuz |
|
| 5 |
3 4
|
sseqtrrdi |
|