length
length — counts the number of elements in a list or array.
Returns
The number of elements in the list or array. If the
argument is not a list or array, returns 0.
Example
Gamma> length(list(#a,#b,#c,#d));
4
Gamma> length([11,13,15,17,19,21]);
6
Gamma> length(sqr(2 + 3));
0
Gamma>