Class orientation and inheritance in modular algebraic nets

We firstly summarize the motivations for combining algebraic nets and the object-oriented approach and then we sketch a syntactic notation called CLOWN (class orientation with nets), whose semantic model is OBJSA nets, i.e., the modular algebraic nets we have developed since some years. Indeed, we believe that it is worth presenting CLOWN because of its net-based notion of (single) inheritance, that we hope can contribute to develop a notion of inheritance adequate for concurrent object-oriented systems, a matter which is still argument of lively discussions