The following functions are used with classes.
CLASS-ABSTRACTP
CLASS-EXISTP
CLASS-REACTIVEP
CLASS-SLOTS
CLASS-SUBCLASSES
CLASS-SUPERCLASSES
DEFCLASS-MODULE
GET-CLASS-DEFAULTS-MODE
GET-DEFCLASS-LIST
GET-DEFMESSAGE-HANDLER-LIST
MESSAGE-HANDLER-EXISTP
SET-CLASS-DEFAULTS-MODE
SLOT-ALLOWED-VALUES
SLOT-CARDINALITY
SLOT-DEFAULT-VALUE
SLOT-DIRECT-ACCESSP
SLOT-EXISTP
SLOT-FACETS
SLOT-INITABLEP
SLOT-PUBLICP
SLOT-RANGE
SLOT-SOURCES
SLOT-TYPES
SLOT-WRITABLEP
SUBCLASSP
SUPERCLASSP