Ordering_is_Equivalent_to_Subset_Relation
Provedorder-theoryproofwikiset-theory
Let be an ordered set. Then there exists a set of subsets of such that where is the relational structure consisting of and the subset relation denotes order isomorphism. Hence any ordering on a set can be modelled uniquely by a set of subsets of that set under the subset relation.
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem Ordering_is_Equivalent_to_Subset_Relation {S : Type _} [PartialOrder S] : ∃ (f : S → Set S), ∀ a b, a ≤ b ↔ f a ⊆ f b := by sorrySource