Hi there. I am using FreeFEM++ to solve a biharmonic equation using Ciarlet-Raviart formulation. I want to know what happens if “solve” has an underconstrained system?

I am asking because I disregard the fact that one of the test functions should be in H^1_0, and I am not getting what I am expecting. The formulation also has two equalities and I provide them as a single one to “solve”.

I will really appreciate your help.

Tom