The symbol "=>" used in program examples should be read "evaluates to." For example,
(* 5 8) => 40
means that the expression (* 5 8) evaluates to the object 40. Or, more precisely: the expression given by the sequence of characters "(* 5 8)" evaluates, in the initial environment, to an object that may be represented externally by the sequence of characters "40". See section 3.3 for a discussion of external representations of objects.