On Derivations of Subtraction Algebras

Year 2012, Volume: 41 Issue: 2, 157 - 168, 01.02.2012

Yong Ho Yon Kyung Ho Kim

Abstract

The aim of this paper is to introduce the notion of derivations of subtraction algebras. We define a derivation of a subtraction algebra X as a function d on X satisfying d(x − y) = (d(x) − y) ∧ (x − d(y)) for all x, y ∈ X. Then it is characterized as a function d satisfying d(x − y) = d(x) − y for all x, y ∈ X. Also we define a simple derivation as a function da on X satisfying da(x) = x−a for all x ∈ X. Then every simple derivation is a derivation and every derivation can be partially a simple derivation on intervals. For any derivation d of a subtraction algebra X, Ker(d) and Im(d) are ideals of X, and X/Ker(d) ∼= Im(d) and X/Im(d) ∼= Ker(d). Finally, we show that every subtraction algebra X is embedded in Im(d) × Ker(d) for any derivation d of X.

Keywords

Subtraction algebra, Derivation, Simple derivation, Non-expansive map, Dual closure operator, Boolean algebra, 2000 AMS Classification: 03 G 25

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