COMMAND:

	The RLaB language has a several commands, they are list
	below. Commands are different than functions, in that they do
	not require parentheses to delimit the function argument(s).

	Commands may not occur anywhere in an expression or statement.
	Therefore, commands must be issued from the command line
	prompt, on a line by themselves.

	Commands:

	help	The help command, without an argument, prints a listing
		of the available help files. The help command can take
		a single argument, that is the name of a help
		file. The named help file will be paged to the screen
		(stdout).

	rfile	The rfile command, without argument(s), prints a
		listing of the available rfiles. The rfile command can
		take one, or several arguments, that are the names of
		help files to be loaded into the current rlab
		environment. The rfile argument(s) can be the full
		file name (ending in `.r'), or a shorthand for the
		file name (without the `.r' extension).

	require	The require command, without argument(s)...

	\	When a backslash is the first character on the command
		line, the rest of the command line is fed to the
		system() function. Thus:

			system ("ls *.r");

		and

			\ ls *.r

		produce the same result.
