A value of an array type consists of components which are all of the same subtype (and hence, of the same type). Each component is uniquely distinguished by an index (for a one-dimensional array) or by a sequence of indices (for a multidimensional array). Each index must be a value of a discrete type and must lie in the correct index range.

an aggregate type whose instances are of fixed size and are ordered

an open type if and only if its element type is an open type

a subtype of another type in the following cases

a supertype of another type, if the other type is a subtype of it

An array type is a composite type whose components are all of the same type. Components are selected by indexing.