matrix

Takes a list of (integer, boolean or enumerated) domains for its indices and a domain for the entries.

Defined by matrix indexed by [COMMA SEPARATED DOMAIN LIST] of [DOMAIN] as demonstrated here.

or by explicity defining values in square brackets like letting M be [0,1] The domain used to index the elements may be specifed too, such that. [0,1] is the same as [0,1; int(1..2)] but different from [0,1; int(0..1)]

They are not ordered, but can be compared using equality operators. Two matrices are only equal if their indices are the same.

Read more about matrix domains here and see them demonstrated here.