reserve x,y,z for Real,
  x3,y3 for Real,
  p for Point of TOP-REAL 3;
reserve p1,p2,p3,p4 for Point of TOP-REAL 3,
  x1,x2,y1,y2,z1,z2 for Real;

theorem Th27:
  p = <* p`1, p`2, p`3 *>
proof
  ex x, y, z being Real st p = <* x, y, z *> by Th1;
  hence thesis;
end;
