Description: Deduction from second Peano postulate generalized to integers. (Contributed by Mario Carneiro, 28-May-2016)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | zred.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℤ ) | |
| Assertion | peano2zd | ⊢ ( 𝜑 → ( 𝐴 + 1 ) ∈ ℤ ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | zred.1 | ⊢ ( 𝜑 → 𝐴 ∈ ℤ ) | |
| 2 | peano2z | ⊢ ( 𝐴 ∈ ℤ → ( 𝐴 + 1 ) ∈ ℤ ) | |
| 3 | 1 2 | syl | ⊢ ( 𝜑 → ( 𝐴 + 1 ) ∈ ℤ ) |