Metamath Proof Explorer


Theorem mrcf

Description: The Moore closure is a function mapping arbitrary subsets to closed sets. (Contributed by Stefan O'Rear, 31-Jan-2015)

Ref Expression
Hypothesis mrcfval.f ⊢ F = mrCls ⁡ C
Assertion mrcf ⊢ C ∈ Moore ⁡ X → F : 𝒫 X ⟶ C

Proof

Step Hyp Ref Expression
1 mrcfval.f ⊢ F = mrCls ⁡ C
2 mrcflem ⊢ C ∈ Moore ⁡ X → x ∈ 𝒫 X ⟼ ⋂ s ∈ C | x ⊆ s : 𝒫 X ⟶ C
3 1 mrcfval ⊢ C ∈ Moore ⁡ X → F = x ∈ 𝒫 X ⟼ ⋂ s ∈ C | x ⊆ s
4 3 feq1d ⊢ C ∈ Moore ⁡ X → F : 𝒫 X ⟶ C ↔ x ∈ 𝒫 X ⟼ ⋂ s ∈ C | x ⊆ s : 𝒫 X ⟶ C
5 2 4 mpbird ⊢ C ∈ Moore ⁡ X → F : 𝒫 X ⟶ C