reserve T for non empty TopSpace,
  a, b, c, d for Point of T;

theorem Th47:
  1RP.0 = 0 & 1RP.1 = 1
proof
  reconsider x = 0, y = 1 as Point of I[01] by BORSUK_1:43;
  thus 1RP.0 = 2*x by Def5
    .= 0;
  thus 1RP.1 = 1RP.y .= 1 by Def5;
end;
