.he 'MISHAP049''Page %'
.fo 'Aaron Sloman''February 78'
.sp
: 49 	Attempt to use a number as a structure
.br
pop11 distinguishes numbers from other objects, like words,
functions, lists and strings. Numbers are represented by
themselves, whereas other objects are "data-structures" and
are represented by "pointers" specifying their address in the
machine. Some functions, e.g. HD and TL expect to be
applied to objects (lists in this case) represented by
pointers. If applied to numbers they complain. Try the
following, and compare the two error messages-
 	hd(0) =>
 	hd("cat") =>
.br
If you try to treat a number as a function, you'll get the
same complaint, e.g.
 	66(x) =>
 	vars f;
 	66 -> f;
 	f(x) =>
.br
Try these.
