The array is a critical data structure in many problems. Operating on components of the array concurrently (for example, using the geometric decomposition pattern) is an effective way to solve these problems in parallel. Concurrent computations may be straightforward to define, but defining how the array is decomposed among a collection of processes or threads can be very difficult. In particular, solutions can require complex book-keeping to map indices between global indices in the original problem domain and local indices visible to a particular thread or process. The solution is to define a distributed array and fold the complicated index algebra into access methods on the distributed array data type. The programmer still needs to handle potentially complex index algebra, but it’s localized to one place and [NOT FINISHED]