Sum all elements of a list

Recursively sums all elements of a list
Usage:

My_sum1=addl( [ 12, 3, 4, 62, 9 ]);
My_sum2=addl( [ [x,y,z], [x,y,z], [x,y,z], [x,y,z]]);

function addl(list, c = 0) = 
 c < len(list) - 1 ? 
 list[c] + addl(list, c + 1) 
 :
 list[c];