+
+;;; subtypep on CONS types wasn't taking account of the fact that a
+;;; CONS type could be the empty type (but no other non-CONS type) in
+;;; disguise.
+(multiple-value-bind (yes win)
+ (subtypep '(and function stream) 'nil)
+ (multiple-value-bind (cyes cwin)
+ (subtypep '(cons (and function stream) t)
+ '(cons nil t))
+ (assert (eq yes cyes))
+ (assert (eq win cwin))))
+
+;;; CONS type subtypep could be too enthusiastic about thinking it was
+;;; certain
+(multiple-value-bind (yes win)
+ (subtypep '(satisfies foo) '(satisfies bar))
+ (assert (null yes))
+ (assert (null win))
+ (multiple-value-bind (cyes cwin)
+ (subtypep '(cons (satisfies foo) t)
+ '(cons (satisfies bar) t))
+ (assert (null cyes))
+ (assert (null cwin))))
+
+(multiple-value-bind (yes win)
+ (subtypep 'generic-function 'function)
+ (assert yes)
+ (assert win))
+;;; this would be in some internal test suite like type.before-xc.lisp
+;;; except that generic functions don't exist at that stage.
+(multiple-value-bind (yes win)
+ (subtypep 'generic-function 'sb-kernel:funcallable-instance)
+ (assert yes)
+ (assert win))
+
+;;; all sorts of answers are right for this one, but it used to
+;;; trigger an AVER instead.
+(subtypep '(function ()) '(and (function ()) (satisfies identity)))