-;;; Used by the interpreter stuff. When it non-NIL, its a function that will
-;;; invoke PPRINT-POP in the right lexical environemnt.
+;;; Used by the interpreter stuff. When it's non-NIL, it's a function
+;;; that will invoke PPRINT-POP in the right lexical environemnt.
+(declaim (type (or null function) *logical-block-popper*))