  An algorithmic computation of the set of unpointed stable homotopy classes of
equivariant fibrewise maps was described in a recent paper of the author and
his collaborators. In the present paper, we describe a simplification of this
computation that uses an abelian heap structure on this set that was observed
in another paper of the author. A heap is essentially a group without a choice
of its neutral element; in addition, we allow it to be empty.
