SAVE filename

	command.  Saves the definitions of all unburied procedures,
	variables, and nonempty property lists in the named file.
	Equivalent to

			to save :filename
			local "oldwriter
			make "oldwriter writer
			openwrite :filename
			setwrite :filename
			poall
			setwrite :oldwriter
			close :filename
			end

	Exceptionally, SAVE can be used with no input and without parentheses
	if it is the last thing on the command line.  In this case, the
	filename from the most recent LOAD or SAVE command will be used.  (It
	is an error if there has been no previous LOAD or SAVE.)

