Barton,
Yes! Thank you for your interest. As pointed before also by Robert
Dodier, buildq is the best way to define this kind of operators. I am
right now learning more about this function, and it is indeed true that
the documentation has nice examples... The only problem was that I did
not know about buildq and it seems that I did not insert the correct
terms for searching in Maxima's help. My fault.
Best regards,
J. A.