+;;; KLUDGE: this is probably because ANSI, in its wisdom (CLHS
+;;; 5.1.2.5) requires implementations to support
+;;; (SETF (APPLY #'AREF ...) ...)
+;;; [and also #'BIT and #'SBIT]. Yes, this is terrifying, and it's
+;;; also terrifying that this sequence of definitions causes it to
+;;; work.
+;;;