Green's formula was put forward by the famous British mathematician and physicist george green in 1928.
Green's formula, Newton-Leibniz formula, Gaussian formula and Stokes formula all reflect the relationship between integral operation and boundary operation, which provides a new way for further theoretical research and practical application of double integral.
When using "curve integration has nothing to do with route", it is required that the integration area is simply connected, so that the integration of any closed curve by Green's formula is zero, but there are few problems in how to calculate the traverse integration in complex connected areas.