An indexed array is a sequential data type--its use can yield no parallelism. Indexed arrays are identical to arrays in languages such as Pascal and Modula-2. They may be indexed and their bounds must be known at compile time. In particular, their bounds may be expressions that are known at compile time, so they may involve constants but not config parameters (Section 4.1.1). The conversion of sequential variables to parallel variables is discussed in Section 6.2.
Note that there is a distinction between nested indexed arrays and multi-dimensional indexed arrays. They are declared differently and accessed differently. Below, a is a nested indexed array and b is a multi-dimensional indexed array.
var a : array [1..10] of array [1..5] of float;
b : array [1..10, 1..5] of float;
a[1][5] := b[1,5];