Project 1: Lexical analyzer for a simple language PASC.  I have three files to
	   form this project.

token.h : define token numbers

lexer.l : lex file defining an automaton to recognize tokens from PASC
          programs.  Error handling, hash table and operations.

driver.c : driving program to test the yylex() function generated from the
           lexer.l file by lex.  It constantly calls the function until the
	   EOF token is reached.  All recognized tokens and/or lexical errors
	   are printed to the standard output.

To run the program type 'make' or 'make -f lex.mk' followed by
'lexy < file.pasc'.