DNA supercoils are formed when DNA forms double strands and then spirals again, including positive supercoils and negative supercoils. Generally speaking, life forms are negative supercoils, which can reduce the number of DNA helices. Positive supercoils can increase the number of helices, and some bacteria and viruses are positive supercoils.

The left-handed helix is derived from the right-handed helix. In fact, ampere rule refers to the right-hand spiral. The definition of simplified names is unambiguous, and it is best not to simplify the left-handed spiral.

Positive super-spiral: two spirals are wound in the right direction. When the external force is twisted in the tightly wound direction, a left-handed super-spiral will be produced to reduce the stress caused by the external force twisting. The helix thus formed is a positive supercoil.

Negative super-spiral: When two spirals wound in the positive direction are twisted in the loose direction by external force, a right-handed super-spiral is produced to reduce the stress caused by external force twisting. The supercoils formed in this way are negative supercoils.

I don't know. Do you understand this? In fact, you can do a similar experiment with a longer rope yourself. Tie the ends of the rope. Then rotate in the direction of DNA double helix. When the rope turns to a certain extent, the spiral rope will produce an automatic spiral in the opposite direction, which is more conducive to your understanding of the definitions of these theoretical formulas.