# The collected works of R. F. C. Walters

These are collected works of R. F. C. Walters (Bob Walters).
Please inform us of any inaccuracies or missing works by either email or opening an "issue" on the GitHub repository.


| Title |Source| Year |
|:------|:-----|:----:|
|[Some Topics in the Theory of Diophantine Approximation](https://github.com/mroman42/walters/blob/main/publications/1967-some-topics-in-the-theory-of-diophantine-approximation.pdf)|MSc thesis, University of Queensland|1967|
|[Alternative Derivation of Some Regular Continued Fractions](https://github.com/mroman42/walters/blob/main/publications/1968-alternative-derivation-of-some-regular-continued-fractions.pdf)|Journal of the Australian Mathematical Society|1968|
|[Some properties of the continued fraction expansion of $(m/n)e^{1/q}$](https://github.com/mroman42/walters/blob/main/publications/1970-some-properties-of-the-continued-fraction-expansion.pdf)|Proc. Camb. Phil. Soc.|1969|
|[An Alternative Approach to Universal Algebra](https://github.com/mroman42/walters/blob/main/publications/1969-an-alternative-approach-to-universal-algebra.pdf)|Reports of the Midwest Category Theory Seminar III|1969|
|[A Categorical Approach to Universal Algebra](https://github.com/mroman42/walters/blob/main/publications/1970-a-categorical-approach-to-universal-algebra.pdf)|PhD thesis, Australian National University|1970|
|[The Comprehensive Factorization of a Functor](https://github.com/mroman42/walters/blob/main/publications/1973-the-comprehensive-factorization-of-a-functor.pdf)|with Ross Street. Bull. Amer. Math. Soc. 79(5): 936-941|1973|
|[Yoneda Structures on 2-categories](https://github.com/mroman42/walters/blob/main/publications/1978-yoneda-structures-on-2-categories.pdf)|with Ross Street. Journal of Algebra|1978|
|[Sheaves and Cauchy-Complete Categories](https://github.com/mroman42/walters/blob/main/publications/1981-sheaves-and-cauchy-complete-categories.pdf)|Cahiers de topologie et géométrie différentielle catégoriques|1981|
|[The Symmetry of the Cauchy-Completion of a Category](https://github.com/mroman42/walters/blob/main/publications/1981-the-symmetry-of-the-cauchy-completion-of-a-category.pdf)|with Renato Betti. Springer Lecture Notes in Mathematics, vol. 962|1981|
|[Sheaves on Sites as Cauchy-Complete Categories](https://github.com/mroman42/walters/blob/main/publications/1982-sheaves-on-sites-as-cauchy-complete-categories.pdf)|Journal of Pure and Applied Algebra|1982|
|[Variation Through Enrichment](https://github.com/mroman42/walters/blob/main/publications/1983-variation-through-enrichment.pdf)|with R. Betti, A. Carboni, and R. Street. Journal of Pure and Applied Algebra|1983|
|[Closed Bicategories and Variable Category Theory](https://github.com/mroman42/walters/blob/main/publications/1985-closed-bicategories-and-variable-category-theory-2020-tac-reprint.pdf)|with R. Betti. Reprints in Theory and Applications of Categories (2020)|1985|
|[On the Nerve of an n-category](https://github.com/mroman42/walters/blob/main/publications/1987-on-the-nerve-of-an-n-category.pdf)|with Michael Johnson. Cahiers de topologie et géométrie différentielle catégoriques|1987|
|[On Completeness of Locally Internal Categories](https://github.com/mroman42/walters/blob/main/publications/1983-on-completeness-of-locally-internal-categories.pdf)|with R. Betti. Journal of Pure and Applied Algebra|1987|
|[Cartesian Bicategories I](https://github.com/mroman42/walters/blob/main/publications/1987-cartesian-bicategories-i.pdf)|with A. Carboni. Journal of Pure and Applied Algebra|1987|
|[An Axiomatics for Bicategories of Modules](https://github.com/mroman42/walters/blob/main/publications/1985-an-axiomatics-for-bicategories-of-modules.pdf)|with A. Carboni and S. Kasangian. Journal of Pure and Applied Algebra|1987|
|[A Note on Context-Free Languages](https://github.com/mroman42/walters/blob/main/publications/1988-a-note-on-context-free-languages.pdf)|Journal of Pure and Applied Algebra|1989|
|[The Free Category with Products on a Multigraph](https://github.com/mroman42/walters/blob/main/publications/1988-the-free-category-with-products-on-a-multigraph.pdf)|Journal of Pure and Applied Algebra|1989|
|[Data Types in Distributive Categories](https://github.com/mroman42/walters/blob/main/publications/1989-data-types-in-distributive-categories.pdf)|Bull. Austral. Math. Soc.|1989|
|[The Calculus of Ends over a Base Topos](https://github.com/mroman42/walters/blob/main/publications/1989-the-calculus-of-ends-over-a-base-topos.pdf)|with R. Betti. Journal of Pure and Applied Algebra|1989|
|[The Duality Between Flow Charts and Circuits](https://github.com/mroman42/walters/blob/main/publications/1990-the-duality-between-flow-charts-pand-circuits.pdf)|with Stefano Kasangian. Bull. Austral. Math. Soc.|1990|
|[Computing quotients of actions of a free category](https://github.com/mroman42/walters/blob/main/publications/1990-computing-quotients-of-actions-of-a-free-category.pdf)|with Sean Carmody. Proceedings of CT 1990|1990|
|[Algebra Objects and Algebra Families for Finite Limit Theories](https://github.com/mroman42/walters/blob/main/publications/1990-algebra-objects-and-algebra-families-for-finite-limit-theories.pdf)|with Michael Johnson. Journal of Pure and Applied Algebra|1992|
|[An Imperative Language Based on Distributive Categories](https://github.com/mroman42/walters/blob/main/publications/1992-an-imperative-language-based-on-distributive-categories.pdf)|Math. Struct. in Comp. Science|1992|
|[Categories and Computer Science](https://github.com/mroman42/walters/blob/main/publications/1992-categories-and-computer-science.pdf)|Cambridge University Press|1992|
|[On Functions and Processors: an automata-theoretic approach to concurrency through distributive categories](https://github.com/mroman42/walters/blob/main/publications/1993-on-functions-and-processors-an-automata-theoretic-approach-to-concurrency-through-distributive-categories.pdf)|with Nicoletta Sabadini. Mathematics Report 93-7, Sydney University|1993|
|[An Automata Theoretic Approach to Concurrency Through Distributive Categories: On Morphisms](https://github.com/mroman42/walters/blob/main/publications/1993-an-automata-theoretic-approach-to-concurrency-through-distributive-categories-on-morphisms.pdf)|with Nicoletta Sabadini and Sebastiano Vigna. Mathematics Report 93-8, Sydney University|1993|
|[On distributive automata and asynchronous circuits](https://github.com/mroman42/walters/blob/main/publications/1993-on-distributive-automata-and-asynchronous-circuits.pdf)|with Nicoletta Sabadini and Henry Weld. Mathematics Report 93-29, Sydney University|1993|
|[Coinverters and categories of fractions for categories with structure](https://github.com/mroman42/walters/blob/main/publications/1993-coinverters-and-categories-of-fractions-for-categories-with-structure.pdf)|with G.M. Kelly and Stephen Lack|1993|
|[Introduction to Extensive and Distributive Categories](https://github.com/mroman42/walters/blob/main/publications/1993-introduction-to-extensive-and-distributive-categories.pdf)|with A. Carboni and S. Lack. Journal of Pure and Applied Algebra|1993|
|[An Imperative Language Based on Distributive Categories II](https://github.com/mroman42/walters/blob/main/publications/1993-an-imperative-language-based-on-distributive-categories-ii.pdf)|with Wafaa Khalil. Theoretical Informatics and Applications|1993|
|[Representations of modules and Cauchy completeness](https://github.com/mroman42/walters/blob/main/publications/1994-representations-of-modules-and-cauchy-completeness.pdf)|with Shu Hao Sun. Cahiers de topologie et géométrie différentielle catégoriques|1994|
|[A notion of refinement for automata](https://github.com/mroman42/walters/blob/main/publications/1994-a-notion-of-refinement-for-automata.pdf)|with N. Sabadini and S. Vigna. Preprint|1994|
|[Fix-Point Semantics for Programs in Distributive Categories](https://github.com/mroman42/walters/blob/main/publications/1995-fix-point-semantics-for-programs-in-distributive-categories.pdf)|with Eric Wagner and Wafaa Khalil. Fundamentica Informaticae|1995|
|[The Todd-Coxeter Procedure and Left Kan Extension](https://github.com/mroman42/walters/blob/main/publications/1991-the-todd-coxeter-procedure-and-left-kan-extensions.pdf)|with Sean Carmody and Mark Leeming. J. Symbolic Computation|1995|
|[A note on recursive functions](https://github.com/mroman42/walters/blob/main/publications/1996-a-note-on-recursive-functions.pdf)|Math. Struct. in Comp. Science|1996|
|[Matrices, machines, and behaviors](https://github.com/mroman42/walters/blob/main/publications/1996-matrices-machines-and-behaviours.pdf)|with Stephen Bloom and Nicoletta Sabadini. Applied Categorical Structures|1996|
|[Bicategories of Processes](https://github.com/mroman42/walters/blob/main/publications/1995-bicategories-of-processes.pdf)|with Piergiulio Katis and Nicoletta Sabadini. Journal of Pure and Applied Algebra|1997|
|[Representing Place-Transition Nets in Span(Graph)](https://github.com/mroman42/walters/blob/main/publications/1997-representing-place-transition-nets-in-span-graph.pdf)|with Piergiulio Katis and Nicoletta Sabadini. Journal of Pure and Applied Algebra|1997|
|[Span(Graph): A Categorical Algebra of Transition Systems](https://github.com/mroman42/walters/blob/main/publications/1997-span-graph-a-categorical-algebra-of-transition-systems.pdf)|with Piergiulio Katis and Nicoletta Sabadini. Algebraic Methodology and Software|1997|
|[Minimal Realization in Bicategories of Automata](https://github.com/mroman42/walters/blob/main/publications/1997-minimal-realization-in-bicategories-of-automata.pdf)|with Robert Rosebrugh and Nicoletta Sabadini. Math. Struct. in Comp. Science|1998|
|[Computing Left Kan Extensions](https://github.com/mroman42/walters/blob/main/publications/1999-computing-left-kan-extensions.pdf)|with M.R. Bush and M. Leeming. Journal of Symbolic Computation|1999|
|[On the Algebra of Feedback and Systems with Boundary](https://github.com/mroman42/walters/blob/main/publications/1999-on-the-algebra-of-feedback-and-systems-with-boundary.pdf)|with Piergiulio Katis and Nicoletta Sabadini. University of Sydney|1999|
|[The Compact Closed Bicategory of Left Adjoints](https://github.com/mroman42/walters/blob/main/publications/1999-the-compact-closed-bicategory-of-left-adjoints.pdf)|with Piergiulio Katis. Math. Proc. Camb. Phil. Soc.|1999|
|[Model checking in Span(Graph)](https://github.com/mroman42/walters/blob/main/publications/2000-model-checking-in-span-graph.pdf)|with Robbie Gates, Piergiulio Katis and Nicoletta Sabadini. Preprint|2000|
|[A Formalization of the IWIM model](https://github.com/mroman42/walters/blob/main/publications/2000-a-formalization-of-the-iwim-model.pdf)|with Piergiulio Katis and Nicoletta Sabadini. Coordination 2000|2000|
|[Automata with Boundary](https://github.com/mroman42/walters/blob/main/publications/2000-automata-with-boundary.pdf)|with Robert Gates, Piergiulio Katis and Nicoletta Sabadini. Preprint|2000|
|[An Automata Model of Distributed Systems](https://github.com/mroman42/walters/blob/main/publications/2001-an-automata-model-of-distributed-systems.pdf)|with Piergiulio Katis, Robert Rosebrugh, and Nicoletta Sabadini. Preprint|2001|
|[Classes of Finite State Automata for which Compositional Minimization is Linear Time](https://github.com/mroman42/walters/blob/main/publications/2001-classes-of-finite-state-automata-for-which-compositional-minimization-is-linear-time.pdf)|with Piergiulio Katis and Nicoletta Sabadini. Preprint|2001|
|[Comparing Cospan-Spans and Tiles via a Hoare Style Process Calculus](https://github.com/mroman42/walters/blob/main/publications/2002-comparing-cospan-spans-and-tiles-via-a-hoare-style-process-calculus.pdf)|with Fabio Gadducci, Piergiulio Katis, Ugo Montanari, and Nicoletta Sabadini. Electronic Notes in Theoretical Computer Science|2002|
|[Feedback, Trace and Fixed-Point Semantics](https://github.com/mroman42/walters/blob/main/publications/2002-feedback-trace-and-fixed-point-semantics.pdf)|with Piergiulio Katis and Nicoletta Sabadini. Theoretical Informatics and Applications|2002|
|[Hierarchical Automata and P-systems](https://github.com/mroman42/walters/blob/main/publications/2003-hierarchical-automata-and-p-systems.pdf)|with Nicoletta Sabadini. Electronic Notes in Theoretical Computer Science|2003|
|[Compositional Minimization in Span(Graph): Some Examples](https://github.com/mroman42/walters/blob/main/publications/2004-compositional-minimization-in-span-graph-some-examples.pdf)|with Piergiulio Katis and Nicoletta Sabadini. Electronic Notes in Theoretical Computer Science|2004|
|[Minimisation and minimal realisation in Span(Graph)](https://github.com/mroman42/walters/blob/main/publications/2004-minimisation-and-minimal-realisation-in-spangraph.pdf)|with Robert Rosebrugh and Nicoletta Sabadini. Mathematical Structures in Computer Science|2004|
|[Timing in the Cospan-Span Model](https://github.com/mroman42/walters/blob/main/publications/2004-timing-in-the-cospan-span-model.pdf)|with A. Cherubini and Nicoletta Sabadini. Electronic Notes in Theoretical Computer Science|2004|
|[Generic Commutative Seperable Algebras and Cospans of Graphs](https://github.com/mroman42/walters/blob/main/publications/2005-generic-commutative-seperable-algebras-and-cospans-of-graphs.pdf)|with Robert Rosebrugh and Nicoletta Sabadini. Theory and Applications of Categories|2004|
|[Cartesian Bicategories II](https://github.com/mroman42/walters/blob/main/publications/2007-cartesian-bicategories-ii.pdf)|with A. Carboni, G.M. Kelly and R. Wood. Theory and Applications of Categories|2007|
|[A universal property of the monoidal 2-category of cospans of finite linear orders and surjections](https://github.com/mroman42/walters/blob/main/publications/2007-a-universal-property-of-the-monoidal-2-category-of-cospans-of-finite-linear-orders-and-surjections.pdf)|with Matias Menni and Nicoletta Sabadini. Preprint|2007|
|[Frobenius Objects in Cartesian Bicategories](https://github.com/mroman42/walters/blob/main/publications/2007-frobenius-objects-in-cartesian-bicategories.pdf)|with Richard Wood. Preprint|2007|
|[On Partita Doppia](https://github.com/mroman42/walters/blob/main/publications/2008-on-partita-doppia.pdf)|with Nicoletta Sabadini. Preprint|2008|
|[Calculating Colimits Compositionally](https://github.com/mroman42/walters/blob/main/publications/2008-calculating-colimits-compositionally.pdf)|with Robert Rosebrugh and Nicoletta Sabadini. Lecture Notes in Computer Science, vol. 5065|2008|
|[The Compositional Construction of Markov Processes](https://github.com/mroman42/walters/blob/main/publications/2009-the-compositional-construction-of-markov-processes.pdf)|with L de Francesco Albasini, and Nicoletta Sabadini. Preprint|2009|
|[Cospans and spans of graphs](https://github.com/mroman42/walters/blob/main/publications/2009-cospans-and-spans-of-graphs.pdf)|with L de Francesco Albasini, and Nicoletta Sabadini. Preprint|2009|
|[An Algebra of Automata which Includes Both Classical and Quantum Entities](https://github.com/mroman42/walters/blob/main/publications/2009-an-algebra-of-automata-which-includes-both-classical-and-quantum-entities.pdf)|with L. de Francesco Albasini and Nicoletta Sabadini. Preprint|2009|
|[The Parallel Composition of Processes](https://github.com/mroman42/walters/blob/main/publications/2009-the-parallel-composition-of-processes.pdf)|with L. de Francesco Albasini and N. Sabadini. Preprint|2009|
|[A Process Algebra for the Span(Graph) Model of Concurrency](https://github.com/mroman42/walters/blob/main/publications/2009-a-process-algebra-for-the-span-graph-model-of-concurrency.pdf)|with Piergiulio Katis and Nicoletta Sabadini. Preprint|2009|
|[The Compositional Construction of Markov Processes II](https://github.com/mroman42/walters/blob/main/publications/2018-the-compositional-construction-of-markov-processes-ii.pdf)|with L. de Francesco Albasini and Nicoletta Sabadini. Preprint|2010|
|[Bicategories of Spans as Cartesian Bicategories](https://github.com/mroman42/walters/blob/main/publications/2010-bicategories-of-spans-as-cartesian-bicategories.pdf)|with Stephen Lack and Richard Wood. Theory and Applications of Categories|2010|
|[Tangled Circuits](https://github.com/mroman42/walters/blob/main/publications/2011-tangled-circuits.pdf)|with Robert Rosebrugh and Nicoletta Sabadini. Preprint|2011|
|算数からはじめよう！　数論  ("Number Theory")|[Iwanami Shoten](https://www.iwanami.co.jp/book/b263071.html)|2011|
|[The Algebra and Geometry of Networks](https://github.com/mroman42/walters/blob/main/publications/2012-the-algebra-and-geometry-of-networks-abstract.pdf)|with Davide Maglia, Nicoletta Sabadini and Filippo Schiavio. Abstract|2012|
|[Blocked Braid Groups](https://github.com/mroman42/walters/blob/main/publications/2013-blocked-braid-groups.pdf)|with D. Maglia and Nicoletta Sabadini. Preprint|2013|
|[Racks and Blocked Braids](https://github.com/mroman42/walters/blob/main/publications/2013-racks-and-blocked-braids.pdf)|with Nicoletta Sabadini. Preprint|2013|
|Working with Aurelio|Il Protagora|2013|
|[On the Geometry and Algebra of Networks with State](https://github.com/mroman42/walters/blob/main/publications/2017-on-the-geometry-and-algebra-of-networks-with-state.pdf)|with Nicoletta Sabadini and Filippo Schiavio. Preprint|2017|


The [University of Sydney](https://www.maths.usyd.edu.au/ut/pub-seek.py?sau=Walters+RFC&pp=3) lists some of the works of R. F. C. Walters.
The nLab has an entry for [Bob Walters](https://ncatlab.org/nlab/show/Bob+Walters).
[ArXiv](https://arxiv.org/search/?searchtype=author&query=Walters%2C+R+F+C) lists some of the works of R. F. C. Walters.
This repository is based on a similar project by Matt Earnshaw [collecting the works of F. W. Lawvere](https://github.com/mattearnshaw/lawvere/).