A semiconductor heterostructure includes a crystalline substrate of a first semiconductor material and a mask disposed over a surface of the crystalline substrate. An input device allows the viewer to move a pointer over different interactive areas of the guide and the function performed when the area is activated is displayed in a contextual help window. Conclusions about the precision with which the polarization transformer to be characterized works can be drawn from the nature and strength or, too, from the absence of changes of control signals of this further polarization transformer, and this can be improved. The presentation style transformer takes a card layout style specification and a card display schema and transforms them into card-based presentation specifications.