@xref{Basic Windows, windowp}.
@item booleanp
-@xref{nil and t, booleanp}
+@xref{nil and t, booleanp}.
@item string-or-null-p
-@xref{Predicates for Strings, string-or-null-p}
+@xref{Predicates for Strings, string-or-null-p}.
@end table
The most general way to check the type of an object is to call the