Dear firedrake users, I try to solve a fourth-order 1d nonlinear problem using the Hermite element in firedrake. The functional space for the weak solution is: $$\mathcal{H}\times \mathcal{H}/times H^{2}_{0} $$ where, $$ \mathcal{H} = \left\lbrace f\in H^2([0,\ell]), \; f(0)=0, \; f'(0)=0 \right\rbrace. $$ I can't impose the boundary conditions correctly. When I compile the code, I get the following error: FiniteElement('Hermite', interval, 3), name=None, index=1, component=None), IndexedProxyFunctionSpace(<firedrake.mesh.MeshTopology object at 0x125a2ce80>, FiniteElement('Hermite', interval, 3), name=None, index=2, component=None), name='None_None_None'), Mesh(VectorElement(FiniteElement('Lagrange', interval, 1), dim=1), 0)), 9) defined on incompatible FunctionSpace! Note the same problem was implemented using FEniCS with C0-interior penalty method, in the reference (sec. 3 eq 3.12-3.13): Enhanced models for the nonlinear bending of planar rods: localization phenomena and multistability by: Matteo Brunetti , Antonino Favata and Stefano Vidoli. I attached the codes to this email. Thanks in advance Smail MERABET