Description: Define the set of positive surreal integers. (Contributed by Scott Fenton, 17-Mar-2025)
Ref | Expression | ||
---|---|---|---|
Assertion | df-nns | ⊢ ℕs = ( ℕ0s ∖ { 0s } ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
0 | cnns | ⊢ ℕs | |
1 | cnn0s | ⊢ ℕ0s | |
2 | c0s | ⊢ 0s | |
3 | 2 | csn | ⊢ { 0s } |
4 | 1 3 | cdif | ⊢ ( ℕ0s ∖ { 0s } ) |
5 | 0 4 | wceq | ⊢ ℕs = ( ℕ0s ∖ { 0s } ) |