University of Birmingham
4pm Tuesday, 2nd February, 2010
Room 4.31/33, Informatics Forum
Nodes of transition systems modulo similarity form a final coalgebra for a suitable endofunctor on the category of posets. Conversely, given a final coalgebra, two nodes are similar when their anamorphic images are related.
These results generalize to an algebraic framework that includes as special cases - upper and lower similarity for transition systems with divergence - bisimilarity - nested similarity.
In the framework developed by Thijs, binary composition of relations must be preserved by relational lifting, but in our framework, it is only laxly preserved. This more liberal condition is what allows nested similarity to be an example.