Continuous nonalgebraic unit interval
ID: continuous-nonalgebraic-unit-interval
Give the real interval its usual total order. Every nonempty directed set has a least upper bound in the real interval, so it is a directed-complete partial order. If , some exceeds ; otherwise would be an upper bound for . Also , since every member of a nonempty is at least zero. For , the increasing sequence , , has least upper bound but never reaches it, so . Together with , this proves the displayed way-below relation.
For each , the elements way-below form , a directed set with least upper bound ; for they form . Thus this is a continuous poset. Its only compact element is zero, so it is not an algebraic partially ordered set.
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