Metamath Proof Explorer
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 |
⊢ ℕs ⊆ ℕ0s |
2 |
1
|
sseli |
⊢ ( 𝐴 ∈ ℕs → 𝐴 ∈ ℕ0s ) |
3 |
|
n0sge0 |
⊢ ( 𝐴 ∈ ℕ0s → 0s ≤s 𝐴 ) |
4 |
2 3
|
syl |
⊢ ( 𝐴 ∈ ℕs → 0s ≤s 𝐴 ) |
5 |
|
nnne0s |
⊢ ( 𝐴 ∈ ℕs → 𝐴 ≠ 0s ) |
6 |
|
0sno |
⊢ 0s ∈ No |
7 |
6
|
a1i |
⊢ ( 𝐴 ∈ ℕs → 0s ∈ No ) |
8 |
|
nnsno |
⊢ ( 𝐴 ∈ ℕs → 𝐴 ∈ No ) |
9 |
7 8
|
sltlend |
⊢ ( 𝐴 ∈ ℕs → ( 0s <s 𝐴 ↔ ( 0s ≤s 𝐴 ∧ 𝐴 ≠ 0s ) ) ) |
10 |
4 5 9
|
mpbir2and |
⊢ ( 𝐴 ∈ ℕs → 0s <s 𝐴 ) |