Mario Román

I am a post-doc at the University of Oxford with Sam Staton. My PhD was at Tallinn University of Technology with Paweł Sobociński. My main interests are category theory, functional programming, foundations for probabilistic programming, formal languages and mathematical notation.

• Publications.
• Preprints.
• Talks
• Posts.
• ArXiv, GitHub, Résumé, CV.
• mromang08@gmail.com

• The Produoidal Algebra of Process Decomposition (PDF, slides 1 and 2).
  Joint with Matt Earnshaw and James Hefford.
  Computer Science Logic (CSL 2024).

• Monoidal Context Theory, PhD Thesis (PDF).
  PhD Thesis. Under the supervision of Pawel Sobocinski.
  Tallinn University of Technology (2023).

• Collages of String Diagrams (PDF, arXiv).
  Joint with Dylan Braithwaite.
  Applied Category Theory (ACT 2023).

• Evidential Decision Theory via Partial Markov Categories (PDF, slides).
  Joint with Elena Di Lavore.
  IEEE Symposium on Logic in Computer Science (LiCS, 2023).

• Optics for Premonoidal Categories (arXiv).
  Joint with James Hefford.
  Applied Category Theory (ACT 2023).

• Monoidal Streams for Dataflow Programming (pdf,slides).
  Joint with Elena Di Lavore and Giovanni de Felice.
  IEEE Symposium on Logic in Computer Science (LiCS, 2022), Distinguished, Kleene Award.

• Span(Graph): a Canonical Feedback Algebra of Open Transition Systems (pdf).
  Joint with Elena Di Lavore, Alessandro Gianola, Nicoletta Sabadini and Paweł Sobociński.
  Software and Systems Modeling, Volume 22, pages 495–520 (2023).

• A Canonical Algebra of Open Transition Systems (pdf).
  Joint with Elena Di Lavore, Alessandro Gianola, Nicoletta Sabadini and Paweł Sobociński.
  Formal Aspects of Component Software (FACS, 2021).

• Promonads and String Diagrams for Effectful Categories (pdf).
  Mario Román.
  Applied Category Theory (ACT, 2022).

• Open Diagrams via Coend Calculus (pdf)
  Mario Román.
  Applied Category Theory (ACT, 2021).

• Cornering Optics (pdf)
  Joint with Chad Nester and Guillaume Boisseau.
  Applied Category Theory (ACT, 2022).

• Profunctor Optics: a Categorical Update (pdf)
  Joint with Clarke, Elkins, Gibbons, Loregian, Milewski and Pillmore.
  Compositionality, Volume 6, Issue 1 (2024).

• Mikrokosmos: an Educational Lambda Interpreter (pdf)
  Under the supervision of Pedro García-Sánchez.
  Journal of Open Source Education (JOSE, 2018).

• Solving Puzzles in Decision Theory (preprint), with Elena Di Lavore.
• String Diagrams for Physical Duoidal Categories (preprint), with Nayan Rajesh.
• Evidential Decision Theory via Partial Markov Categories (NWPT 2024), with Elena Di Lavore.
• Universal Properties of Asynchronous Message Passing (abstract), with Matt Earnshaw.
• Context-Free Languages of String Diagrams (preprint), with Matt Earnshaw.
• Effectful Trace Semantics via Effectful Streams (preprint), with Filippo Bonchi and Elena Di Lavore.
• String Diagrams for Premonoidal Categories (arXiv), with Paweł Sobociński.
• Coinductive Streams in Monoidal Categories (arXiv), with Elena Di Lavore and Giovanni de Felice.
• Polar Interleavings for Deadlock-Free Message-Passing (preprint), with Matt Earnshaw and Chad Nester.
• Symmetric monoidal automata (preprint), with Elena Di Lavore.
• Presentations of Premonoidal Categories by Devices (preprint), with Matt Earnshaw and Chad Nester.
• Contouring Prostar Autonomous Categories (preprint), with Matt Earnshaw and James Hefford.
• Be Careful with Duoidal Coherence (preprint).
• Comb Diagrams for Discrete-Time Feedback (preprint).
• Timing monoidal lax categories (preprint).
• Distributive laws of promonads (preprint).
• Composing optics (preprint).

• String Diagrams for Premonoidal Categories, at the departamental seminar, Pisa.
• Notes on profunctors, at the PUDDLE seminar, Oxford.
• Effectful Streams, at CMCS'24, Luxembourg (remote).
• Polar Shuffles, at the CHESS-PTSPC'24 workshop, Tallinn.
• The Produoidal Algebra of Process Decomposition, at CSL'24, Naples.
• Notes on Fox’s theorem, at a Tallinn retreat, Matsalu park.
• Polar Interleavings, at NWPT'23, Västerås.
• Monoidal Context Theory, PhD Defence, Tallinn.
• Finding the Right Abstractions Workshop 2023, Oxford.
• Collages of String Diagrams, at ACT'23, Maryland.
• Timing Processes, at the Bob Walters Tribute 2023, Tallinn.
• Optics: the Algebra of Monoidal Context, at MFPS'23, Bloomington, Indiana.
• The Produoidal Algebra of Process Decomposition, at the Ottawa Logic Seminar.
• From theories to categories at the Lawvere Memorial Meeting, Tallinn.
• String diagrams of string diagrams at TallCat group meetings, Tallinn.
• Evidential Decision Theory via Partial Markov Categories at NWPT'22, Bergen.
• Premonoidal Streams, at the Intercats Seminar of the Topos Institute.
• Monoidal Streams for Dataflow Programming, at LiCS'22.
• Monoidal Streams for Dataflow Programming, at NWPT'21, Reykjavik.
• Notes on A Graphical View at TallCat Seminar, Tallinn.
• Monoidal Streams for Dataflow Programming, at the Bath Mathematical Foundations Seminar.
• Promonads and String Diagrams for Effectful Categories at ACT'22, Strathclyde.
• Notes on Compositional Markov Processes at the ACT'22 Adjoint School, Strathclyde.
• Monoidal Profunctors at Compositional Methods Retreat, Raudsilla.
• A Canonical Algebra of Transition Systems at ACT'21, Cambridge.
• A Canonical Algebra of Transition Systems at FACS'21, Grenoble.
• Picturing Multivariable Adjunctions, the 2-Chu construction at TallCat Seminar, Tallinn.
• Lesson on Monoidal Categories at the Category Theory course, Tallinn.
• Open Diagrams via Coend Calculus at ACT'20, MIT.
• Profunctor Optics: a Categorical Update at ACT'20, MIT.
• Profunctor Optics: a Categorical Update at NWPT'19, Tallinn.
• Profunctor Optics: a Categorical Update at SYCO 5, Birmingham.
• Profunctor Optics: a Categorical Update at MFoCS Dissertation, Oxford.

Activities.

• Compositionality, Executive Board, 2023-2025.
• Applied Category Theory Conference 2024 (ACT24), Program Committee.
• Applied Category Theory Conference 2023 (ACT23), Program Committee.
• Applied Category Theory Conference 2022 (ACT22), Program Committee.
• Mathematical Foundations of Programming Semantics (MFPS 40th), Local Organization.
• Applied Category Theory Conference 2024 (ACT24), Local Organization.

Awards, grants, distinctions.

• EuroProofNet Short Term Scientific Mission visitor to Elena Di Lavore, 2024.
• EuroProofNet Short Term Scientific Mission host for Elena Di Lavore, 2024.
• Kleene Award at LiCS'22, joint with Elena Di Lavore and Giovanni de Felice, 2022.
• Distinguished paper at LiCS'22, joint with Elena Di Lavore and Giovanni de Felice, 2022.
• Undergraduate Research Fellowship, Department of Algebra, Granada, 2018.
• Award to the best undergraduate thesis in Mathematics, Granada, 2018.

Teaching.

• TA for the Applied Category Theory Adjoint School, Glasgow, under Nicoletta Sabadini, 2022.
• TA for Category Theory, Tallinn University of Technology, under Pawel Sobocinski, 2020.
• TA for Functional Programming, Tallinn University of Technology, under Edward Morehouse, 2020.

Reviewing.

• Logical Methods in Computer Science (LMCS), reviewer.
• Mathematical Structures in Computer Science (MSCS), reviewer.
• Compositionality, reviewer.
• ACM/IEEE Symposium on Logic in Computer Science, reviewer (LiCS'20, LiCS'22, LiCS'23).
• Symposium on Principles of Programming Languages, reviewer (POPL'25).
• Applied Category Theory Conference, reviewer (ACT20, ACT21, ACT22, ACT23, ACT24).
• Symposium on Compositional Structures, reviewer (SYCO6, SYCO7, SYCO8, SYCO9).
• International Conf. on Curr. Trends in Th. and Pract. of Comp. Sci., reviewer (SOFSEM2023).
• International Conf. on Principles of Knowledge Representation and Reasoning, reviewer (KR2023).
• Coalgebraic Methods in Computer Science, reviewer (CMCS24).

Positions.

• Postdoc, Research Assistant. University of Oxford, under Sam Staton, 2023-2025.
• PhD in Software Science. Tallinn University of Technology, under Paweł Sobociński, 2019-2023.
• MSc in Mathematics and Foundations of Computer Science, University of Oxford, 2019.
• Bachelor Degree in Computer Engineering, University of Granada, 2012-2018.
• Bachelor Degree in Mathematics, University of Granada, 2012-2018.