let me go on record as saying that binomial(n,k) and C(n,k) are (and always will be) the same in the EIS - and that their definition is the official one given by if(k<0,0,prod(i=0,k-1,n-i)/k!) and used by every writer on combinatorics (especially Riordan and Comtet, and possibly even by Euler) It is unfortunate that Maple's definition is wrong. NJAS