Metamath Proof Explorer


Theorem elfzo2nn

Description: A member of a half-open range of integers starting at 2 is a positive integer. (Contributed by AV, 5-Apr-2026)

Ref Expression
Assertion elfzo2nn ⊢ K ∈ 2 ..^ N → K ∈ ℕ

Proof

Step Hyp Ref Expression
1 elfzo2 ⊢ K ∈ 2 ..^ N ↔ K ∈ ℤ ≥ 2 ∧ N ∈ ℤ ∧ K < N
2 eluz2nn ⊢ K ∈ ℤ ≥ 2 → K ∈ ℕ
3 2 3ad2ant1 ⊢ K ∈ ℤ ≥ 2 ∧ N ∈ ℤ ∧ K < N → K ∈ ℕ
4 1 3 sylbi ⊢ K ∈ 2 ..^ N → K ∈ ℕ