λεῖψις · leipsis — LSJ
omission, τοῦ ἄρθρου A.D. Synt. 78.9.
failure, lack, ἀγαθῶν Cat.Cod.Astr. 8(1).182.
Math., negative term in an algebraic expression, opp. ὕπαρξις, λ. ἐπὶ λεῖψιν πολλαπλασιασθεῖσα ποιεῖ ὕπαρξιν a minus multiplied by a minus gives a plus, Dioph. 1 Def. 9: dat. λείψει c. gen., minus, Id. 2.21.