Hi,

I am a beginner at Fenics. Is there any way to set up a constraint condition for the nodes? I am testing with a basic heat conduction problem. and created a simple bifurcation mesh:

editor.add_vertex(0, np.array([0.0,0.0,0.0]))

editor.add_vertex(1, np.array([0.0279,0,0]))

editor.add_vertex(2, np.array([0.0279,0.0,0]))

editor.add_vertex(3, np.array([0.043032,0.015132,0]))

editor.add_vertex(4, np.array([0.0279,0.0,0]))

editor.add_vertex(5, np.array([0.043032,-0.015132,0]))

editor.add_cell(0, np.array([0,1], dtype=np.uintp))

editor.add_cell(1, np.array([2,3], dtype=np.uintp))

editor.add_cell(2, np.array([4,5], dtype=np.uintp))

Is that possible to set a constrain that node1=node2+node4?

Many Thanks!