@INPROCEEDINGS{BBV04a,
  title = {{Subtyping-Inheritance Conflicts: The Mobile Mixin Case}},
  author = {Bettini, Lorenzo and Bono, Viviana and Venneri, Betti},
  booktitle = {Proc. of Third IFIP International Conference on Theoretical Computer Science (TCS 2004)},
  editor = {J-J. Levy and  E.W. Mayr and  J.C. Mitchell},
  pages = {451--464},
  abstract = {In sequential class- and mixin-based settings, subtyping is
        essentially a relation on objects: no subtype relation is defined on
        classes and mixins, otherwise there would be conflicts with
        the inheritance mechanism, creating type un-safety.  Nevertheless,
        a width-depth subtyping relation
        on class and mixin types is useful in the realm of mobile and
        distributed processes, where object-oriented code may be exchanged
        among the sites of a net. In our proposal, classes and mixins
        become ``first-class citizens'' at communication time, and
        communication is ruled by a type-safe width-depth subtyping
        relation.},
  year = {2004},
  url = {http://rap.dsi.unifi.it/phpbibliography/files/momitype.pdf},
  publisher = {Kluwer Academic Publishers},
}