SHAPIRO'S PROLOG DEBUGGER
                        Written by E. Y. Shapiro
                      Contributed by Norbert Fuchs,
            Department of Computer Science, Zurich University
                   Shelved on the 3rd of October 1988


This is the program from Appendix II (pp 185-213) of Algorithmic Program
Debugging, MIT Press, 1982.

Some  of  the parts  are  interesting  and  useful for  other  purposes.

The  program contains  very  few  comments, because  it  comes from  the
Appendix of  a book whose  main text describes  it in great  detail. You
will need the book before you can make sense of this code. [JNP]             


SIZE:
    40 kilobytes.


CHECKED ON EDINBURGH-COMPATIBLE (POPLOG) PROLOG :
    No.


PORTABILITY :
    Contains % comments.


INTERNAL DOCUMENTATION :
    Very brief description of each main section.