funcallable-standard-object provides the default
:direct-superclasses for instances of
funcallable-standard-class and its subclasses.
funcallable-standard-object is implemented as described in AMOP except for a different order in the class precedence list.
In AMOP the class precedence list is
(funcallable-standard-object standard-object function t)
whereas in LispWorks the class precedence list is
(funcallable-standard-object function standard-object t)
LispWorks is like this to be compliant with the rules in the ANSI Common Lisp Standard.
The AMOP class precedence list implies a class precedence for
generic-function which violates the last sentence in ANSI Common Lisp 4.2.2 Type Relationships. See
LispWorks User Guide and Reference Manual - 20 Sep 2017