Hello every one,

I have a problem with 6 unknown fields (ux1,uy1,ux2,uy2,p1,p2) and 6 test functions (vx1,vy1,vx2,vy2,q1,q2). My geometry is a square (0,1)(0,1) divided in two equal rectangle by a vertical internal line at (x=0.5). I need to force the equality between the two fields ux1 and ux2 at the internal line. I tried to add the integral

int1d(Th, internal_line)(q2*(ux1-ux2))

but it doesn’t work. Is there a trick to do it?

Thank you.