People write about the Report definition of gcd x y as of greatest integer that divides x and y, and mention > gcd 0 0 = 0 But 2 also divides 0, because 2*0 = 0. Does the Report specify that gcd 0 0 is not defined? For an occasion: probably, it is better to specify this. ----------------- Serge Mechveliani mechvel@botik.ru