reserve p,q,r for FinSequence,
  x,y for object;

theorem Th36:
  for R being Relation, a,b being object st R reduces a,b holds
  a,b are_convergent_wrt R & a,b are_divergent_wrt R &
  b,a are_convergent_wrt R & b,a are_divergent_wrt R
proof
  let R be Relation, a,b be object;
  R reduces a,a & R reduces b,b by Th12;
  hence thesis;
end;
