Description: A nonnegative integer is an integer. (Contributed by Mario Carneiro, 28-May-2016)
Ref | Expression | ||
---|---|---|---|
Hypothesis | nnzd.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℕ ) | |
Assertion | nnzd | ⊢ ( 𝜑 → 𝐴 ∈ ℤ ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nnzd.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℕ ) | |
2 | 1 | nnnn0d | ⊢ ( 𝜑 → 𝐴 ∈ ℕ_{0} ) |
3 | 2 | nn0zd | ⊢ ( 𝜑 → 𝐴 ∈ ℤ ) |