Metamath Proof Explorer


Theorem zrisefaccl

Description: Closure law for rising factorial. (Contributed by Scott Fenton, 5-Jan-2018)

Ref Expression
Assertion zrisefaccl ⊢ A ∈ ℤ ∧ N ∈ ℕ 0 → A N ‾ ∈ ℤ

Proof

Step Hyp Ref Expression
1 zsscn ⊢ ℤ ⊆ ℂ
2 1z ⊢ 1 ∈ ℤ
3 zmulcl ⊢ x ∈ ℤ ∧ y ∈ ℤ → x ⁢ y ∈ ℤ
4 nn0z ⊢ k ∈ ℕ 0 → k ∈ ℤ
5 zaddcl ⊢ A ∈ ℤ ∧ k ∈ ℤ → A + k ∈ ℤ
6 4 5 sylan2 ⊢ A ∈ ℤ ∧ k ∈ ℕ 0 → A + k ∈ ℤ
7 1 2 3 6 risefaccllem ⊢ A ∈ ℤ ∧ N ∈ ℕ 0 → A N ‾ ∈ ℤ