& abs()
 
  Syntax: abs(<number>)
 
  This function returns the absolute value of its argument. 
  The <number> may be a floating point number, as well as return a 
  floating point number.
 
  Example:
 
  > say abs(4)
  You say "4"
  > say abs(-4)
  You say "4"
  > say abs(0)
  You say "0"