reserve n,m,k for Nat,
  x,X for set,
  A for Subset of X,
  A1,A2 for SetSequence of X;

theorem Th67:
  lim_sup (A1 (/\) A2) c= lim_sup A1 /\ lim_sup A2
proof
  (A1 (/\) A2).n = A1.n /\ A2.n by Def1;
  hence thesis by KURATO_0:13;
end;
