* (defclass class-a-coming-first (class-a class-b) ())
#<STANDARD-CLASS CLASS-A-COMING-FIRST {584BE6AD}>

* (defclass class-b-coming-first (class-b class-a) ())
#<STANDARD-CLASS CLASS-B-COMING-FIRST {584C744D}>

* (another-fn (make-instance 'class-a-coming-first))
:CLASS-A

* (another-fn (make-instance 'class-b-coming-first))
:CLASS-B