-;;; :DECLARED = from a declaration.
-;;; :ASSUMED = from uses of the object.
-;;; :DEFINED = from examination of the definition.
-;;; FIXME: The :DEFINED assumption that the definition won't change
-;;; isn't ANSI. KLUDGE: CMU CL uses function type information in a way
-;;; which violates its "type declarations are assertions" principle,
-;;; and SBCL has inherited that behavior. It would be really good to
-;;; fix the compiler so that it tests the return types of functions..
-;;; -- WHN ca. 19990801
+;;; :ASSUMED = from uses of the object
+;;; :DEFINED = from examination of the definition
+;;; :DECLARED = from a declaration
+;;; :DEFINED trumps :ASSUMED, and :DECLARED trumps :DEFINED.
+;;; :DEFINED and :ASSUMED are useful for issuing compile-time warnings,
+;;; and :DECLARED is useful for ANSIly specializing code which
+;;; implements the function, or which uses the function's return values.