:method-combination CL-USER> (defclass foo1 nil nil) ;=> #<STANDARD-CLASS FOO1> CL-USER> (defclass foo2 (foo1) nil) ;=> #<STANDARD-CLASS FOO2> CL-USER> (defclass foo3 (foo2) nil) ;=> #<STANDARD-CLASS FOO3> ;; [ + and append list max min nconc or progn ] が利用可能らしい CL-USER> (defgeneric method1 (x)</standard-class></standard-class></standard-class>…