  A coset relation algebra is one embeddable into some full coset relation
algebra, the latter is an algebra constructed from a system of groups, a
coordinated system of isomorphisms between quotients of these groups, and a
system of cosets that are used to "shift" the operation of relative
multiplication. We prove that the class of coset relation algebras is
equationally axiomatizable (that is to say, it is a variety), but no finite set
of equations suffices to axiomatize the class (that is to say, the class is not
finitely axiomatizable).
