Metamath Proof Explorer


Theorem 0risefac

Description: The value of the zero rising factorial at natural N . (Contributed by Scott Fenton, 17-Feb-2018)

Ref Expression
Assertion 0risefac ⊢ N ∈ ℕ → 0 N ‾ = 0

Proof

Step Hyp Ref Expression
1 0cn ⊢ 0 ∈ ℂ
2 nnnn0 ⊢ N ∈ ℕ → N ∈ ℕ 0
3 risefallfac ⊢ 0 ∈ ℂ ∧ N ∈ ℕ 0 → 0 N ‾ = − 1 N ⁢ -0 N _
4 1 2 3 sylancr ⊢ N ∈ ℕ → 0 N ‾ = − 1 N ⁢ -0 N _
5 neg0 ⊢ − 0 = 0
6 5 oveq1i ⊢ -0 N _ = 0 N _
7 0fallfac ⊢ N ∈ ℕ → 0 N _ = 0
8 6 7 eqtrid ⊢ N ∈ ℕ → -0 N _ = 0
9 8 oveq2d ⊢ N ∈ ℕ → − 1 N ⁢ -0 N _ = − 1 N ⋅ 0
10 neg1cn ⊢ − 1 ∈ ℂ
11 expcl ⊢ − 1 ∈ ℂ ∧ N ∈ ℕ 0 → − 1 N ∈ ℂ
12 10 2 11 sylancr ⊢ N ∈ ℕ → − 1 N ∈ ℂ
13 12 mul01d ⊢ N ∈ ℕ → − 1 N ⋅ 0 = 0
14 4 9 13 3eqtrd ⊢ N ∈ ℕ → 0 N ‾ = 0