c-----------------------------------------------------------------------
subroutine get_grp(grp,irec,ifil,iset,ipri)
c-----------------------------------------------------------------------
implicit double precision (a-h,o-z)
dimension grp(*)
Reads a vector of redundancy group numbers from a given record irec, ifil. No defaults
for irec, ifil apply. The set number iset must be provided.
If ipri 
, information about the redundancy set is printed (one line).