Using the program "yapl" ("yapl++"), which implements a compiler for the
     for the language, YAPL (YAPL++), specified in the syntax diagrams for
     YAPL (YAPL++).

     The syntax diagrams for YAPL and YAPL++ can be reached via a link from the
     Web page www.lehigh.edu/~ejk0/cse109.html

     The program yapl (yapl++) is stored in /proj/csc109/bin/yapl
     (/proj/csc109/bin/yapl++).

     The call is
          yapl <input> <output> <code>
          (yapl++ <input> <output> <code>)
     where <input> is the file of yapl (yapl++) code, <output> is the
     name of the file where the results of the compilation gets stored,
     and <code> is the file where the sml code (if generated) gets
     stored.

     Any text following "#" is considered a comment and is ignored,
     including the "#".

     Following the "end" there can appear data. If the program in
     <input> compiles, then an 'END' is appended to the end of the code
     in <code> and then all the text follwing "end" in <input> gets
     appended to <code>, after the 'END'.