= MPI_Reduce =
Reduces values on all processes to a single value

= Synopsis =
{{{
  #include "mpi.h"
  int MPI_Reduce ( void *sendbuf, void *recvbuf, int count, MPI_Datatype datatype, MPI_Op op, int root, MPI_Comm comm )
}}}

= Input Parameters =
{{{
  sendbuf   address of send buffer (choice)
  count     number of elements in send buffer (integer)
  datatype  data type of elements of send buffer (handle)
  op 	    reduce operation (handle)
  root 	    rank of root process (integer)
  comm 	    communicator (handle)
}}}

= Output Parameter =
{{{
  recvbuf   address of receive buffer (choice, significant only at root) 
}}}