<theory> A set X is directed under some relation, <= (less than or equal), if it is non-empty and if for any two elements x and y there exists an element z such that x <= z and y <= z. I.e. all pairs have an upper bound.
(1994-11-11)
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Nearby terms: directed acyclic graph « directed graph « Directed Oc « directed set » Direct Inward Dialing » directional coupler » Directly Executable Test Oriented Language
