Metamath Proof Explorer


Theorem hashbccl

Description: The binomial set is a finite set. (Contributed by Mario Carneiro, 20-Apr-2015)

Ref Expression
Hypothesis ramval.c ⊢ C = a ∈ V , i ∈ ℕ 0 ⟼ b ∈ 𝒫 a | b = i
Assertion hashbccl ⊢ A ∈ Fin ∧ N ∈ ℕ 0 → A C N ∈ Fin

Proof

Step Hyp Ref Expression
1 ramval.c ⊢ C = a ∈ V , i ∈ ℕ 0 ⟼ b ∈ 𝒫 a | b = i
2 1 hashbcval ⊢ A ∈ Fin ∧ N ∈ ℕ 0 → A C N = x ∈ 𝒫 A | x = N
3 pwfi ⊢ A ∈ Fin ↔ 𝒫 A ∈ Fin
4 3 birani ⊢ A ∈ Fin ∧ N ∈ ℕ 0 → 𝒫 A ∈ Fin
5 ssrab2 ⊢ x ∈ 𝒫 A | x = N ⊆ 𝒫 A
6 ssfi ⊢ 𝒫 A ∈ Fin ∧ x ∈ 𝒫 A | x = N ⊆ 𝒫 A → x ∈ 𝒫 A | x = N ∈ Fin
7 4 5 6 sylancl ⊢ A ∈ Fin ∧ N ∈ ℕ 0 → x ∈ 𝒫 A | x = N ∈ Fin
8 2 7 eqeltrd ⊢ A ∈ Fin ∧ N ∈ ℕ 0 → A C N ∈ Fin