reserve a,b,c,d for Real;

theorem Th2:
  a <= b implies Closed-Interval-TSpace(a,b) is closed
proof
  assume a <= b;
  then the carrier of Closed-Interval-TSpace(a,b) = [.a,b.] by TOPMETR:18;
  then
  for A be Subset of R^1 holds A = the carrier of Closed-Interval-TSpace(a
  ,b) implies A is closed by Th1;
  hence thesis by BORSUK_1:def 11;
end;
