Strong formulation

[paabl0_9]

Hi, i need to write this variational problem on its strong formulation.

mesh Th=square(10,10);
fespace Vh(Th,P1);
Vh uh,vh; //
func f=1; //
func g=0; //
problem laplace(uh,vh,solver=GMRES,tgv=1e5) = //
int2d(Th)( dx(uh)dx(vh) + dy(uh)dy(vh) ) //
int1d(Th,1)( uhvh) //
int1d(Th,1)( vh) //
int2d(Th)( fvh ) //
on(2,3,4,uh=g) ; //
laplace; //
plot(uh,ps=“LaplaceP1.eps”,value=true); //

Thanks for help.

[frederichecht (Frédéric Hecht)]

$$- \Delta u = f = 1 \mbox{ in } \Omega = ]0,1[^2$$
remember the border $\Gamma_i$ is
i: 1: bottom , 2 right, 3 top , 4 left
border of the square

on $\Gamma_1$ we have fourier / robin condtion:
${\partial(u)\over \partial n} = 1 - u $

On 3 other boundary $\Gamma_2$ ,$\Gamma_2$ ,$\Gamma_4$ the Boundary condition is

u = g = 0

the image of latex :