104 (2*(*devel_psi_un[1])(nz_un-1, 0, 0, 0)+
105 2*(*devel_psi_deux[1])(nz_deux-1, 0, 0, 0)+
106 (*devel_n_deux[1])(nz_deux-1, 0, 0, 0) +
107 (*devel_n_un[1])(nz_un-1, 0, 0, 0))
108 / fabs ((*devel_n_deux[1])(nz_deux-1, 0, 0, 0) +
109 (*devel_n_un[1])(nz_un-1, 0, 0, 0)) ;