Packaging looks good except, I would move
/usr/share/doc/Singular-3.0.0-1/info/singular.hlp
to
/usr/share/info/singular.info
possible bzip2-ing it (it's quite big with 1.7MB) so that info/pinfo can
find it.
Also it seems that cygwin packages do not include the release number in
the package doc directory and the various cygwin specific README's.
So maybe change
/usr/share/doc/Cygwin/singular-XXXX-3.0.0-1.README
to
/usr/share/doc/Cygwin/singular-XXXX-3.0.0.README
and
/usr/share/doc/Singular-3.0.0-1
to
/usr/share/doc/Singular-3.0.0
Not a showstopper so.