A semi-topological classification of line figures

In this paper a subclass of line figures, which are finite unions of arcs, is considered. We call such a figure a form. To each form a numerical sequence related to the Euler characteristic of the underlying space of the form is attached. We prove that a form can be decomposed into simple ones. On the basis of this decomposition, to each form a matrix, as a way of arithmetization of the structure of the form, is attached. Finally, this leads to a semi-topological classification of forms. Then, invariant properties of this classification are taken as a basis for character recognition.