Order_of_Elements

 The elements of an array form a sequence known as the array element
 order.  The position of an element in this sequence is its
 subscript order value.

 The elements of an array are stored as a linear sequence of values.
 A one-dimensional array is stored with its first element in the
 first storage location and its last element in the last storage
 location of the sequence.  A multidimensional array is stored so
 that the leftmost subscripts vary most rapidly.  This is called the
 order of subscript progression.

 In an array section, the subscript order of the elements is their
 order within the section itself.  For example, if an array is
 declared as B(20), the section B(4:19:4) consists of elements B(4),
 B(8), B(12), and B(16).  The subscript order value of B(4) in the
 array section is 1; the subscript order value of B(12) in the
 section is 3.