Group congruences on regular semigroups.
Groupoids and the associative law XII. (Representable cardinal functions)
Half-automorphisms of transformation semigroups
Homogeneous quotients of semigroups.
Homomorphisms of a Completely Simple Semigroup onto a Group
Homomorphisms of free contents.
Homomorphisms of sandwich semigroups and sandwich near-rings.
Homomorphisms of semigroups of binary relations.
Homomorphisms of semilattices of semigroups.
Ideal nil-extensions of semigroups with semimodular congruence lattices.
Idempotent cross-sections of J-classes.
Idempotent Endomorphisms on Standard Threads.
Idempotent separating congruences on an orthodox semigroup via the least inverse congruence.
In memory of Jaroslav Ježek
Infinite products in monoids.
Inner extrapolation of semigroup translations.
Interpolation property in semigroups.
Isomorphisms of wreath products of monoids, I.
Joins and meets of congruences on a regular semigroup.
Kurepa's functional equation on semigroups.
The functional equation to which the title refers is:F(x,y) + F(xy,z) = F(x,yz) + F(y,z),where x, y and z are in a commutative semigroup S and F: S x S --> X with (X,+) a divisible abelian group (Divisibility means that for any y belonging to X and natural number n there exists a (unique) solution x belonging to X to nx = y).