(DEFINE-CLASS MY-CLASS)

(DEFINE-CLASS-METHOD (MY-CLASS 'DO-SOMETHING-WITH SOME-PARAMETER)
    (DISPLAY "I am the class -- ")
    (DISPLAY SELF)
    (NEWLINE)
    (DISPLAY "You sent me the parameter ")
    (DISPLAY SOME-PARAMETER)
    (NEWLINE))

(DEFINE-METHOD (MY-CLASS 'DO-SOMETHING-WITH SOME-PARAMETER)
    (DISPLAY "I am an instance of the class --  ")
    (DISPLAY SELF)
    (NEWLINE)
    (DISPLAY "You sent me the parameter ")
    (DISPLAY SOME-PARAMETER)
    (NEWLINE))

(MY-CLASS 'DO-SOMETHING-WITH 'FOO)

(DEFINE MY-INSTANCE (MY-CLASS 'NEW))

(MY-INSTANCE 'DO-SOMETHING-WITH 'BAR)