The Kelvin–Stokes theorem (named Lord Kelvin and George Stokes), also known as the curl theorem, is a theorem in vector calculus on . Given a vector field, the theorem relates the integral of the curl of the vector field over some surface, to the line integral of the vector field around the boundary of the surface. The Kelvin–Stokes theorem is a special case of the “generalized Stokes' theorem.” In particular, a vector field on can be considered as a 1-form in which case curl is the exterior derivative.