Description: A surreal positive integer is non-zero. (Contributed by Scott Fenton, 15-Apr-2025)
Ref | Expression | ||
---|---|---|---|
Assertion | nnne0s | ⊢ ( 𝐴 ∈ ℕs → 𝐴 ≠ 0s ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eldifsni | ⊢ ( 𝐴 ∈ ( ℕ0s ∖ { 0s } ) → 𝐴 ≠ 0s ) | |
2 | df-nns | ⊢ ℕs = ( ℕ0s ∖ { 0s } ) | |
3 | 1 2 | eleq2s | ⊢ ( 𝐴 ∈ ℕs → 𝐴 ≠ 0s ) |