function solver=assembly_rbc(mesh,solver)


P=speye(solver.dof);
phi=mesh.PBCIndex(:,3)*mesh.PBCphi;
nbrPBC=length(phi);
for i=1:nbrPBC
    P(mesh.PBCIndex(i,2),mesh.PBCIndex(i,1))=phi(i);
end

tempIndex=sort([mesh.PBCIndex(:,2);mesh.origIndex]);
P(:,tempIndex)=[];

solver.P=P;

end