Boundary Conditions in PDE MODEL

i create PDE model

g is exported from PDE Tololbox

model = createpde;
geometryFromEdges(model,g);
applyBoundaryCondition(model,'dirichlet','Edge',[1 2 3 12 11 10 9 6],'u',0);
pdegplot(model,'EdgeLabels','on')
xlim([-1.2,1.2])
axis equal
generateMesh(model,'Hmax',0.02,'GeometricOrder','Linear');

(this square is sum of little squares: R1+R2+R3+R4)

but applyBoundaryCondition dont specify Edge 12, 11, 10 ,9 boundary condition u=0.

It is, what i get

Here, Edges 1 2 3 and 6 are equal 0, but 12 11 10 9 are not, but i specify them

applyBoundaryCondition(model,'dirichlet','Edge',[1 2 3 12 11 10 9 6],'u',0);

[Torsten]

You can't specify boundary conditions at internal boundaries.