tests: point to point communication
success criterion: baton successfully passed to all processes.
tests: various syntax, reduction operations, and point-to-point
exchanges
success criterion: reductions across processes give the same answer
as local, analytical calculations.
tests: point to point communication of all supported types
success criterion: data is successfully sent between all
process pairs.
tests: point to point communication
success criterion: determines the lower triangular matrix elements
within epsilon.