+;;; Def-Boolean-Attribute Name Attribute-Name*
+;;;
+;;; Define a new class of Boolean attributes, with the attributes
+;;; having the specified ATTRIBUTE-NAMES. NAME is the name of the
+;;; class, which is used to generate some macros to manipulate sets of
+;;; the attributes:
+;;;
+;;; NAME-attributep attributes attribute-name*
+;;; Return true if any of the named attributes are present, false
+;;; otherwise. When set with SETF, updates the place Attributes
+;;; setting or clearing the specified attributes.
+;;;
+;;; NAME-attributes attribute-name*
+;;; Return a set of the named attributes.