Hi Abdullah,
having hybrid variables for the pressure you should be able to condense also the element-wise pressure. Yes, you do so by setting the coupling-type.
for debugging, you can dump and check element-matrices as follows :
Thanks for your reply. I now know that I am on the correct route! Also printelmat will definitely be useful for debugging purposes.
However, what I mean is if I try to solve the system described in Eqs. (54)-(55), i.e. eliminating both element momentum and elemnent pressure, -for test purposes using a direct solver- I get the correct solution. However, if I try to solve the system as described in Eqs. (65)-(66) (by setting the coupling type of element pressure unknowns to interface dofs for example), I get a solution which does not make sense.
Attached I am sending an implementation of the method. I am using the variable eliminate_up to switch between condensing both u and p and condensing only u. I am setting the coupling type in lines 74-76. I appreciate your time.