|\^/| MAPLE V ._|\| |/|_. Copyright (c) 1981-1990 by the University of Waterloo. \ MAPLE / All rights reserved. MAPLE is a registered trademark of <____ ____> Waterloo Maple Software. | Type ? for help. > x:=4; i:=5; x := 4 i := 5 > x^i; 1024 > sum(i^2,i=1..n); Error, (in sum) summation variable previously assigned, second argument evaluates to, 5 = 1 .. n > i; 5 > sum('i^2','i'=1..n); 3 2 1/3 (n + 1) - 1/2 (n + 1) + 1/6 n + 1/6 > i := 'i'; i := i > sum(i^2,i=1..n); 3 2 1/3 (n + 1) - 1/2 (n + 1) + 1/6 n + 1/6 > quit