




We may use Stokes' Theorem to deduce this by applying it to a tiny rectangle
normal to the w_{1} direction with sides obeying one of dw_{2 }=
0 and dw_{3 }= 0, and then cyclically permuting the indices.
The surface integral in Stokes' theorem then becomes
u_{2}u_{3}dw_{2}dw_{3}(v)_{1}
while the path integrals become
which gives us: