Abstract

The algebra of all binary relations on a given set is the most important example of a relation algebra . In this note we will examine the possible isomorphisms within some subclasses of a closely related class ; A is a relation set algebra with base U if its Boolean reduct is a field of sets with unit element 2 U, its universe A contains the identity relation on U and it is closed under the operations −1 and |, where R |S = { : ∈ R, ∈ S for some z} and R−1 = { : ∈ R} for any R, S ⊆ 2 U. The class of all relation set algebras is denoted by Rs