nLab
Günter Hotz

Günter Hotz (born 16.11.1931) is a german mathematician and computer scientist and a professor emeritus of the University of the Saarland, Saarbrücken, Germany.

Hotz is one of the “pioneers” of computer science in Germany and has been strongly involved in establishing computer science as a scientific discipline in Germany in the early 70s.

His scientific contributions include automata theory, formal languages, VLSI design, information theory, topology and more.

Hotz has a mathematical background in algebraic topology. He wrote his dissertation thesis in 1958 in Göttingen under supervision of Kurt Reidemeister about a topic from Knot theory. In 2008, he published an efficient algorithm for deciding the equivalence of Knots.

In his 1965 habilitation thesis “Eine Algebraisierung des Syntheseproblems von Schaltkreisen” (EIK, Bd. 1, (185-205), Bd, 2, (209-231), English title would be “An algebraisation of the synthesis problem of switching circuits) he used the theory of monoidal categories for describing the syntax and semantics of switching circuits.

In this thesis, he introduced string diagrams (under the name “plane nets”) as a topological representation of the morphisms in free monoidal categories. This probably is the first formal definition of string diagrams in the literature.

In his 1966 publication “Eindeutigkeit und Mehrdeutigkeit formaler Sprachen”, EIK, Bd. 2 (235-246), (in German, English title would be “Unambiguity and ambiguity of formal languages”), he uses the theory of monoidal categories and string diagrams to give an exact mathematical definition for the derivations in Semi-Thue systems and Chomsky grammars.

In the early 80s, monoidal categories have been generalized to bicategories of logic-topological nets and used as the mathematical foundation of the VLSI design system “CADIC”.

Last revised on February 18, 2017 at 05:43:33. See the history of this page for a list of all contributions to it.