+;;; Until sbcl-0.7.13.7, union of CONS types when the CDRs were the
+;;; same type gave exceedingly wrong results
+(assert (null (subtypep '(or (cons fixnum single-float)
+ (cons bignum single-float))
+ '(cons single-float single-float))))
+(assert (subtypep '(cons integer single-float)
+ '(or (cons fixnum single-float) (cons bignum single-float))))