  We describe how isogenies between principally polarized abelian surfaces
(PPAS) with real multiplication (RM) can be decomposed into elementary isogeny
types. This leads to a strategy for enumerating the isogeny class of a given
PPAS with RM. This note is part of an ongoing work with R. van Bommel, S.
Chidambaram, and E. Costa and is not indended for separate publication.
