public static void main(String[] args) throws Exception {
		String inFile=null;

		if(args.length>0)
			inFile=args[0];
		else
			inFile = "default.txt";

		InputStream inStream = new FileInputStream(inFile);
		LizpLexer lexer = new LizpLexer(new ANTLRFileStream(inFile));
		CommonTokenStream tokens = new CommonTokenStream(lexer);
		LizpParser parser = new LizpParser(tokens);

		ParserRuleContext tree = parser.program();
		tree.inspect(parser);
		LizpSuperListener lsl = new LizpSuperListener();
		ParseTreeWalker walker = new ParseTreeWalker();
		walker.walk(lsl, tree);
	}