Metamath Proof Explorer


Theorem fznn0

Description: Characterization of a finite set of sequential nonnegative integers. (Contributed by NM, 1-Aug-2005)

Ref Expression
Assertion fznn0 ⊢ N ∈ ℕ 0 → K ∈ 0 … N ↔ K ∈ ℕ 0 ∧ K ≤ N

Proof

Step Hyp Ref Expression
1 0z ⊢ 0 ∈ ℤ
2 nn0z ⊢ N ∈ ℕ 0 → N ∈ ℤ
3 elfz1 ⊢ 0 ∈ ℤ ∧ N ∈ ℤ → K ∈ 0 … N ↔ K ∈ ℤ ∧ 0 ≤ K ∧ K ≤ N
4 1 2 3 sylancr ⊢ N ∈ ℕ 0 → K ∈ 0 … N ↔ K ∈ ℤ ∧ 0 ≤ K ∧ K ≤ N
5 df-3an ⊢ K ∈ ℤ ∧ 0 ≤ K ∧ K ≤ N ↔ K ∈ ℤ ∧ 0 ≤ K ∧ K ≤ N
6 elnn0z ⊢ K ∈ ℕ 0 ↔ K ∈ ℤ ∧ 0 ≤ K
7 6 anbi1i ⊢ K ∈ ℕ 0 ∧ K ≤ N ↔ K ∈ ℤ ∧ 0 ≤ K ∧ K ≤ N
8 5 7 bitr4i ⊢ K ∈ ℤ ∧ 0 ≤ K ∧ K ≤ N ↔ K ∈ ℕ 0 ∧ K ≤ N
9 4 8 bitrdi ⊢ N ∈ ℕ 0 → K ∈ 0 … N ↔ K ∈ ℕ 0 ∧ K ≤ N