SUM _ _ _ _ _ _ _ _ _ _ _ _ operator

The operator sum returns the indefinite or definite summation of a given expression.

syntax:

where <expr> is the expression to be added, <k> is the control variable (a kernel), and <lolim> and <uplim> are the optional lower and upper limits. If <uplim> is not supplied the upper limit is taken as <k>. The Gosper algorithm is used. If there is no closed form solution, the operator returns the input unchanged.

examples:

sum(4n**3,n); 

   2    2
  n  *(n   + 2*n + 1)


sum(2a+2k*r,k,0,n-1);

  n*(2*a + n*r - r)