Continuum_Property
Provedanalysiscompletenessproofwikireal-numberssupremum
Let be a non-empty subset of the set of real numbers such that is bounded above. Then admits a supremum in . This is known as the '''least upper bound property''' of the real numbers. Similarly, let be a non-empty subset of the set of real numbers such that is bounded below. Then admits an infimum in . This is sometimes called the '''greatest lower bound property''' of the real numbers. The two properties taken together are called the '''continuum property of '''. This can also be stated as The set of real numbers is Dedekind complete.
Preamble
import Mathlib.Analysis.Complex.Basic
Formal statement
theorem Continuum_Property (S : Set ℝ) (hS : S.Nonempty) (hbdd : BddAbove S) : ∃ x : ℝ, IsLUB S x := by sorry
Source