
       Summations consist of the highlighted Greek character %ä% followed
   followed by an optional bounds of summation which is enclosed in curly
   brackets "{...}" followed by an argument enclosed in parenthesis.  An
   optional step factor may be specified.

   %Examples%

   %ä%{j=0,ì,2}(a[j]), ä(b[j])

   %Usage%

   S : %ä%{j=1,ì}(1/j^2)


