Description: The set of all positive surreal integers exists. (Contributed by Scott Fenton, 17-Mar-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | nnsex | |- NN_s e. _V | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | df-nns |  |-  NN_s = ( NN0_s \ { 0s } ) | |
| 2 | n0sex | |- NN0_s e. _V | |
| 3 | 2 | difexi |  |-  ( NN0_s \ { 0s } ) e. _V | 
| 4 | 1 3 | eqeltri | |- NN_s e. _V |