& add()
 
  Syntax: add(<number1>,<number2>[,<numberN>]...)
 
  This function returns the result of adding its arguments together. 
  You may add up to 30 numbers in one add() call. 
  The <numberN> may be a floating point number, and a floating point 
  result is returned.
 
  Example:
 
  > say add(2,4)
  You say "6"
  > say add(5,3,7,-4)
  You say "11"
 
  See also: inc(), dec(), div(), mod(), mul(), sub().