REDUCE includes a module for printing S-expressions in a standard format. The Standard Lisp function for this purpose is PRETTYPRINT which takes a Lisp expression and prints the formatted equivalent.
Users can also have their REDUCE input printed in this form by use of the switch DEFN. This is in fact a convenient way to convert REDUCE (or Rlisp) syntax into Lisp. off msg; will prevent warning messages from being printed.
NOTE: When DEFN is on, input is not evaluated.