Relations, residuals, regular interiors, and relative regular equivalence

Given a relation α (a binary sociogram) and an a priori equivalence relation π, both on the same set of individuals, it is interesting to look for the largest equivalence πo that is contained in and is regular with respect to α. The equivalence relation πo is called the regular interior of π with respect to α. The computation of πo involves the left and right residuals, a concept that generalized group inverses to the algebra of relations. A polynomial-time procedure is presented (Theorem 11) and illustrated with examples. In particular, the regular interior gives meet in the lattice of regular equivalences: the regular meet of regular equivalences is the regular interior of their intersection. Finally, the concept of relative regular equivalence is defined and compared with regular equivalence.

Killing fields. [Review of Rebel land: among Turkey's forgotten peoples by Christopher de Bellaigua]

Alev Adil explores a region still enraged by a 'crime on the sly'

[Reviews] Turkey and the European Union: prospects for a difficult encounter

Book review of 'Turkey and the European Union: Prospects for a Difficult Encounter', edited by Esra Lagro and Knud Erik Jorgensen, Basingstoke and New York: Palgrave Macmillan, 2007 Pp. xii þ 240; 1 table; 1 figure; index; ISBN 9780230019553; £47.00 (hb).