Metamath Proof Explorer


Theorem mrerintcl

Description: The relative intersection of a set of closed sets is closed. (Contributed by Stefan O'Rear, 3-Apr-2015)

Ref Expression
Assertion mrerintcl ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C → X ∩ ⋂ S ∈ C

Proof

Step Hyp Ref Expression
1 rint0 ⊢ S = ∅ → X ∩ ⋂ S = X
2 1 adantl ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S = ∅ → X ∩ ⋂ S = X
3 mre1cl ⊢ C ∈ Moore ⁡ X → X ∈ C
4 3 ad2antrr ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S = ∅ → X ∈ C
5 2 4 eqeltrd ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S = ∅ → X ∩ ⋂ S ∈ C
6 simp2 ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S ≠ ∅ → S ⊆ C
7 mresspw ⊢ C ∈ Moore ⁡ X → C ⊆ 𝒫 X
8 7 3ad2ant1 ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S ≠ ∅ → C ⊆ 𝒫 X
9 6 8 sstrd ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S ≠ ∅ → S ⊆ 𝒫 X
10 simp3 ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S ≠ ∅ → S ≠ ∅
11 rintn0 ⊢ S ⊆ 𝒫 X ∧ S ≠ ∅ → X ∩ ⋂ S = ⋂ S
12 9 10 11 syl2anc ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S ≠ ∅ → X ∩ ⋂ S = ⋂ S
13 mreintcl ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S ≠ ∅ → ⋂ S ∈ C
14 12 13 eqeltrd ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S ≠ ∅ → X ∩ ⋂ S ∈ C
15 14 3expa ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C ∧ S ≠ ∅ → X ∩ ⋂ S ∈ C
16 5 15 pm2.61dane ⊢ C ∈ Moore ⁡ X ∧ S ⊆ C → X ∩ ⋂ S ∈ C