<stavros.macrakis@verizon.net> skriver: >rat(489)^2281,modulus:3293 I would like to define an operator like this: infix(§); a§b:=rat(a),modulus:b; and then make for instance 489^2281§3293; - but maxima won't accept it. How can I do it correctly? I wonder why this operator is not a standard built-in operator in maxima? Yours, Poul Riis