add-method
  Is the generic-function argument a generic function or the name of a
  generic function or may it only be a generic function?  Note that
  add-method would seem to be the programmatic counterpart to defmethod,
  but add-method in fact requires that the generic function already exist
  (e.g., that it has already been defined with make-generic-function.)

argument-precedence-order
  Did we in fact agree that argument-precedence-order deals with only
  required arguments?  I have written function.tex as if this were true.