ALIST produces a listing file  containing  IMP  source  code  with  line
numbers  and the relative addresses of the code produced for each source
line.
It is run as follows:-
.R ALIST
*listfile=source file,rel file
The default extensions are .LST, .IMP  and  .REL  respectively  and  for
missing  filenames,  the  source filename.  The four following lines are
equivalent.
*file.LST = file.IMP, file.REL
*file = file, file
*file, file
*file
