MDARRAY sizelist					(library procedure)
(MDARRAY sizelist origin)

	outputs a multi-dimensional array.  The first input must be a list
	of one or more positive integers.  The second input, if present,
	must be a single integer that applies to every dimension of the array.
	Ex: (MDARRAY [3 5] 0) outputs a two-dimensional array whose members
	range from [0 0] to [2 4].