output  -- Command, one input.  Abbreviation: op
     This command is used in a user procedure  which  is  meant  to  be  an
     operation.  The input to this command becomes the output from the user
     procedure.  Please don't be confused by the fact that  the  user  pro-
     cedure is an operation, while the output primitive procedure is a com-
     mand used in that procedure.  Example:

     to nickname :person
     if equalp :person [Peter Parker] [output "Spiderman]
     if equalp :person [Lamont Cranston] [output "Shadow]
     output first :person
     end
