# Writing a constraint for a jump

Dear colleagues;
I have trouble creating a jump over an edge for my field, \psi, a P2 element.
I am solving, where q and \mu are known, and r is a multiplier:

Over a square, with an extracted circle from the center as follow:

I want a difference of \psi over the blue dashed line: i.e., \psi|_{below}=\psi|_{above}+2 \pi for instance, while \nabla \psi remains continuos on both sides (without cutting or any alterations to the domain).

What terms some I add to the

solve Mahdi( \psi , v ) = int2d(Th)( r*(dx(\psi)*dx(v) + dy(\psi)dy(v)) ) + int2d(Th)( ( \mu x-rqx )dx(v) + ( \mu y-rqy )*dy(v) )

Is there such a thing available in FreeFem for a P2 element?

Please accept my apologies for my weak knowledge.