Hybrid b- and h-formulations for the solution of the 2D magnetostatic
problem are presented. These formulations can be written in such a may
that the resulting system matrices are identical up to the coefficien
t related to the material properties. Thus after the evaluation of the
required matrix terms two complementary solutions of the problem are
obtained easily with the total computational cost of almost one. The c
omplementarity of the solutions gives a good basis for the adaptive me
sh refinement. In the derivation of the formulations differential form
s, which best describe the underlying idea, have been used.