reserve n for Element of NAT,
  i for Integer,
  a, b, r for Real,
  x for Point of TOP-REAL n;

theorem Th5:
  R^1 | (R^1 [#]REAL) = R^1
proof
  [#]R^1 = R^1([#]REAL) by TOPMETR:17;
  hence thesis by PRE_TOPC:def 5;
end;
