As follows:

V stands for operation in mathematics. Mathematically, operation is a behavior, and a new quantity is obtained through possible combinations of known quantities. The essence of operation is the mapping between sets. Generally speaking, operation refers to algebraic operation, which is the correspondence in a set.

In mathematics, v stands for volume and speed. Technical terms of volume and geometry. When the space occupied by an object is a three-dimensional space, the size of the space occupied is called the volume of the object. The international unit of volume system is cubic meters. One-dimensional space objects (such as straight lines) and two-dimensional space objects (such as squares) are all zero volumes.

In physics, speed is used to indicate the speed and direction of an object's motion. Velocity is numerically equal to the ratio of the displacement of the object movement to the time taken for the displacement to occur. The calculation formula of speed is v = δ s/δ t, and the unit of speed in the international system of units is meters per second.

For a pair of elements A and B taken out in sequence in set A, there is a unique third element C corresponding to it in set A, which is called the operation defined in set A..

From this operation, we can get two operations, that is, one of A and B is expected and C is known. The operation thus obtained is called the inverse operation of the original operation. For example, addition is the operation of finding a+b=c when A and B are known, then the operation of finding B when A and C are known, or the operation of finding A when B and C are known, is the inverse operation of addition, which is called subtraction.