Metamath Proof Explorer


Theorem nnsgt0

Description: A positive integer is greater than zero. (Contributed by Scott Fenton, 15-Apr-2025)

Ref Expression
Assertion nnsgt0 ( 𝐴 ∈ ℕs → 0s <s 𝐴 )

Proof

Step Hyp Ref Expression
1 nnssn0s s ⊆ ℕ0s
2 1 sseli ( 𝐴 ∈ ℕs𝐴 ∈ ℕ0s )
3 n0sge0 ( 𝐴 ∈ ℕ0s → 0s ≤s 𝐴 )
4 2 3 syl ( 𝐴 ∈ ℕs → 0s ≤s 𝐴 )
5 nnne0s ( 𝐴 ∈ ℕs𝐴 ≠ 0s )
6 0sno 0s No
7 6 a1i ( 𝐴 ∈ ℕs → 0s No )
8 nnsno ( 𝐴 ∈ ℕs𝐴 No )
9 7 8 sltlend ( 𝐴 ∈ ℕs → ( 0s <s 𝐴 ↔ ( 0s ≤s 𝐴𝐴 ≠ 0s ) ) )
10 4 5 9 mpbir2and ( 𝐴 ∈ ℕs → 0s <s 𝐴 )