There is a close path p in that cannot be deformed to a point, but traversing p twice, i.e., can be deformed to a point in . It indicates that is not simply-connected. Since corresponds to the real projective space , we cannot fully draw in three dimensional space. The plate trick simply shows that the first rotation of 360° cannot be deformed to a single point because the arm is twisted, but if we have one more rotation of 360° to the same direction, i.e., rotation of 720°, can go back to the original state.