Intersection_is_Subset_of_Union
Provedproofwikiset-intersectionset-union
Intersection is Subset of Union
Preamble
import Mathlib.Data.Set.Basic
Formal statement
theorem Intersection_is_Subset_of_Union {α : Type _} (S T : Set α) : S ∩ T ⊆ S ∪ T := by sorry