Runtime.NativeDataParallelOwned

---- gradient partitioning ---- With gradient partitioning (ReduceToRegionOwners) each coordinate owner r receives only the sums of its own coordinates and the mass: every owner's leaf is projected onto r's coordinates (padded to the most any owner holds) and reduced over the same tree in the same order as the full sum, then delivered along the tree path to r alone (CombineDeliverTo). Each coordinate's sum is the replicated sum's word bit for bit.

548def dpoGradientOwners =
549  (lambda unrestricted c : Nat .
550    (lambda unrestricted u : Nat .
551      (lambda unrestricted system : (family DataParallelSystem c u) .
552        (naturalMinimum (dpOwners c u system) (dpK c u system)))))