In types PERMUTATIONS and SUBSETS the default elements are 1,2,3,... These elements can be replaced by other symbols by a specification SYMBOLS=<list_of_symbols>. Example: COMB P,CUR+1 / P=SUBSETS,5,3 SYMBOLS=a,b,c,d,e Subsets of size 3 of 5 elements: N[P]=10 a b c a b d a b e a c d a c e a d e b c d b c e b d e c d e C = Other forms of COMB