NODES

	outputs a list of two numbers.  The first represents the number of
	nodes of memory currently in use.  The second shows the maximum
	number of nodes that have been in use at any time since the last
	invocation of NODES.  (A node is a small block of computer memory
	as used by Logo.  Each number uses one node.  Each non-numeric
	word uses one node, plus some non-node memory for the characters
	in the word.  Each array takes one node, plus some non-node
	memory, as well as the memory required by its elements.  Each
	list requires one node per element, as well as the memory within
	the elements.)  If you want to track the memory use of an
	algorithm, it is best if you invoke GC at the beginning of each
	iteration, since otherwise the maximum will include storage that
	is unused but not yet collected.