theorem Th77:
  for I being set
  for A being ManySortedSet of I
  ex R being ManySortedRelation of A
  st R = I-->{} & R is terminating
  proof
    let I be set;
    let A be ManySortedSet of I;
    set R = I-->{};
    for i being set st i in I holds R.i is Relation of A.i by XBOOLE_1:2;
    then reconsider R as ManySortedRelation of A by MSUALG_4:def 1;
    take R;
    thus R = I-->{};
    let i be set;
    thus thesis;
  end;
