reserve i for Nat,
  j for Element of NAT,
  X,Y,x,y,z for set;

theorem Th35:
  for x,y being variable holds
  <*x,y*> is quasi-loci iff vars x = {} & x <> y & vars y c= {x}
proof
  let x,y be variable;
A1: rng <*x*> = {x} by FINSEQ_1:38;
A2: <*x*> is quasi-loci iff vars x = {} by Th34;
  y in {x} iff y = x by TARSKI:def 1;
  hence thesis by A1,A2,Th31,Th32;
end;
