We were champions before you came, and we were champions after you left. There was no champion before you came, and there was still no champion after you left. It can be said that Green's formula has done great harm to Durant. The above is the meaning and stem of the closed loop of Green's formula.
Closed-loop control is a basic concept of cybernetics.
Green's formula is a mathematical formula, which describes the close relationship between the curve integral of coordinates along the closed curve L on the plane and the double integral on the closed area D surrounded by the curve L, and is generally used for the total differential quadrature of binary functions.
Closed-loop refers to a control relationship in which the controlled output returns to the control input in some way and exerts control influence on the input. System control mode with feedback information.