It's OK with the cvs version of compar. I guess this bug is fixed:
(%i1) load("compar.lisp")$
(%i2) sign(max(7,x) - max(6,x));
(%o2) pnz
Barton
-----maxima-bounces at math.utexas.edu wrote: -----
>With 5.15.0, I get
>
>(%i1) sign(max(7,x) - max(6,x));
>Maxima encountered a Lisp error: