Transformation of Reduction Systems a View on Proving Correctness Transformation of Reduction Systems a View on Proving Correctness

was centered around two questions: 1. What are good notions for proving correctness of transformations for Reduction Systems? 2. Does Thatte's transformation preserve connuence for the class of weakly persistent systems? Jan Bergstra helped me with the rst question and was my supervisor in the rst part of the project. We had long talks about computer science, university, and other things. Those talks were extremely instructive. At a particular moment, Jan led me into the room of Piet Rodenburg. Piet would become my supervisor for the second part of the project. He literally taught me how read and write mathematics and meticulously read various drafts of this thesis. Moreover, he xed my attention on the second question and provided the counterexample to a claim in Verma's proof. We spent a lot of time searching for proofs and counterexamples of Verma's theorem, but did not nd the answer yet. Nonetheless, I still haven't lost hope that we will eventually solve the problem and I hope Piet hasn't either. Thank you Jan and Piet. I would also like to thank Wan Fokkink, Jasper Kamperman and Jaco van de Pol for the discussions we had about the rst question. They helped me to acquire an opinion on the subject. Furthermore, acknowledgements are due to Jan Willem Klop for explaining to me some things about Term Rewriting and stimulating me to investigate simulation relations. Finally, I thank my friends of the Faculty and Anna for support in various ways.