Automorphism groups and factor automata of strongly connected automata. Independence of the equational axioms for iteration theories. Multilevel nested relational structures. Andrew Odlyzko . 17th Annual ACM Symposium on the Theory of Computing, May 6-8, 1985.
White pebbles help.
Self-organizing sequential search and Hilbert's inequalities. Meyer , E.-R. Olderog , and J. I. Zucker . Transition systems, metric spaces, and ready sets in the semantics of uniform concurrency. The complexity of parallel search. A randomized proof system, and a hierarchy of complexity classes.