/*D
   MPI_Group_difference - Makes a group from the difference of two groups

Synopsis:
.vb
int MPI_Group_difference(MPI_Group group1, MPI_Group group2,
                         MPI_Group *newgroup)
.ve

Input Parameters:
+ group1 - first group (handle)
- group2 - second group (handle)

Output Parameters:
. newgroup - difference group (handle)

Notes:
The generated group contains the members of 'group1' that are not in 'group2'.

.N ThreadSafe

.N Fortran

.N Errors
.N MPI_SUCCESS
.N MPI_ERR_ARG
.N MPI_ERR_GROUP
.N MPI_ERR_OTHER

.seealso: MPI_Group_free
D*/

