I.12.11 Vector field circulation

Condition: Check the Stokes formula for the vector field \( \vec{a}=(y-z) \vec{\imath}+(z-x) \vec{\jmath}+(x-y) \vec{k} \), taking the circle \( x^{2}+y^{2}=a^{2}, z=0, \quad \) and for the surface of integration - any surface passing through this circle.