Lachlan McPheat

(he/him)

As of August 2024, I am a research associate at The Alan Turing Institute, working on the Robust Inference with Probabilistic Answer Set Programs Scaffolds for Large Language Models.

From May to August 2024 I was visiting the Bekki Lab at Ochanomizu University in Tokyo, studying Bekki's Dependent Type Semantics of natural language.

From June to September 2022 I interned at Quantinuum's Oxford office, working under Bob Coecke in graphical Discourse Representation Theory.

I finished my PhD at the PPLV , UCL Computer Science, supervised by Mehrnoosh Sadrzadeh. I studied methods of modelling referential phenomena in natural lanugage using distributional-compositional semantics. So far this involves defining categorical interpretations of variants of Lambek Calculus with modalities which resolve coreference syntactically and experimenting with the semantics of this resolution using a variety of composition and language models.

Broader research interests include: Transparency and Interpretability in AI/ML, Computational Linguistics, NLP, Distributional-Compositional Semantics, Categorical Semantics, Category Theory and Dependent Type Theory.

Research Activities

• Publications

1. An Empirical Study of Conformal Prediction in LLM with ASP Scaffolds for Robust Reasoning
   Joint work with Navdeep Kaur, Alessandra Russo, Anthony G. Cohn and Pranava Madhyastha
   Accepted at ICLR 2025 Open Science for Foundation Models Workshop
   Preprint: ArXiv
2. Donkey Sentences Via DisCoCat
   Joint work with Daphne Wang
   EPTCS
3. A Quantum Natural Language Processing Approach to Pronoun Resolution
   Joint work with Hadi Wazni, Kin Ian Lo and Mehrnoosh Sadrzadeh
   Preprint: ArXiv
4. Vector Space Semantics for Lambek Calculus with Soft Subexponentials
   Joint work with Mehrnoosh Sadrzadeh and Hadi Wazni
   To appear in LNCS
   Preprint: ArXiv
5. Anaphora and Ellipsis in Lambek Calculus with a Relevant Modality: Syntax and Semantics
   Joint work together with Mehrnoosh Sadrzadeh, Adrian Correia and Alexi Toumi
   Published in Journal of Cognitive Science link
   Preprint: ArXiv
6. Categorical Vector Space Semantics for Lambek Calculus with a Relevant Modality
   Joint work together with Mehrnoosh Sadrzadeh, Hadi Wazni and Gijs Wijnholds
   Published in Journal of Compositionality link
   Conference version: EPTCS
   Preprint: ArXiv

• Presentations

• Donkey sentences via DisCoCat
  Modalities in Substructural Logics: Applications at the Interfaces o Logic, Language and Computation, Ljubljana, SVN
  7 Aug 23
• Discourse analysis using modal lambek calculus
  Natural Language Syntax and Statistical Semantics with Modal Lambek Calculus, Ljubljana, SVN
  4 Aug 23
• Distributional Compositional Models of Discourse (Thesis Abstract)
  The 35th Swedish Artificial Intelligence Society annual workshop, Karlskrona, SWE
  13 Jun 23
• Making Modalities (Lax) Monoidal
  Applied Category Theory 2022, Glasgow, SCO
  18 Jul 22 (video & notes)
• Fock spaces and multiplexing as a model of discourse
  Workshop on QNLP and Fock Spaces, UCL, ENG
  20 Jun 22
  
• Categorical Models of Discourse
  LGBTQ+STEM Conference, UCL, ENG
  hosted by the UCL LGBTQ+STEM network
  9 Jun 2022
  Awarded "best presentation"
• Vector Space Semantics for Lambek Calculus with Soft Subexponentials
  Logical Aspects of Computational Linguistics, Montpellier University, FR
  14 Dec 21
• Categorical Models of Discourse
  British Logic Colloquium, PhD Day, Annual Meeting 2021, Durham University, ENG
  1 Sep 21
• Anaphora and Ellipsis in Lambek Calculus with a Relevant Modality: Syntax and Semantics
  Applied Category Theory 2021, Cambridge University, ENG
  15 Jul 21
• Winograd Schema Challenge via Plausibility
  PPLV reading group, UCL, ENG
  7 Jun 21
• Mathematical Foundations for a Compositional Distributional Model of Meaning
  PPLV reading group, UCL, ENG
  25 Jan 21
• Derivations of Anaphora and Ellipsis in Lambek Calculus with a Relevant Modality
  SemSpace2020, University of Utrecht, NL
  6 Aug 20 (video)
  
• Categorical Vector Space Semantics for Lambek Calculus with a Relevant Modality
  Applied Category Theory 2020, MIT, US
  6-10 Jul 20
  Keynote presentation with Hadi Wazni (video)
  

• Participations

• MOSAIC workshop
  TU Wien, Vienna, AUT
  27 - 29 Sep 23
• Learning with Small Data
  University of Gothenburg, Gothenburg, SWE
  11 - 12 Sep 23
• Modalities in Substructural Logics: Applications at the Interfaces of Logic, Language and Computation
  University of Ljubljana, Ljubljana SVN
  7 - 8 Aug 23
• ESSLLI 2023
  University of Ljubljana, Ljubljana SVN
  31 Jul - 11 Aug 23
• The 35th Swedish Artificial Intelligence Society (SAIS'23) annual workshop
  Blekinge Tekniska Högskola, Karlskrona SWE
  11 - 12 Jun 23
• Oxford Machine Learning Summer School
  Oxford University, Oxford, ENG
  8 - 10 May 23
• (Dis)embodiement
  Göteborgs Universitet, Gothenburg, SWE
  15 - 16 Sep 22
• ESSLLI 2022
  National University of Ireland Galway, Galway, IRE
  8 - 19 Aug 22
• ACT 2022
  Strathclyde University, Glasgow, SCO
  Speaker
  18 - 22 Jul 22
• QPL 2022
  Oxford University, Oxford, ENG
  27 Jun - 1 Jul 22
• UCL LGBTQ+STEM Conference 2022
  UCL, London, ENG
  9 Jun 22
• QNLP 2022
  Oxford University, Oxford, ENG
  30 - 31 May 22
• Logical Aspects of Computational Linguistics 2021
  (run jointly with Logic and Algorithms in Computational Linguistics 2021),
  Montpellier University, FR
  Speaker
  13 - 17 Dec 21
• British Logic Colloquium, PhD Day 2021
  Durham University, Durham, ENG
  Speaker
  1 Sep 21
• ESSLLI 2021
  Online
  26 Jul - 13 Aug 21
• Logic Colloquium 2021
  Posnań University, Posnań, PL
  Speaker
  19 - 24 Jul 21
• Applied Category Theory 2021
  Cambridge University, Cambridge, ENG
  Speaker
  12 - 16 Jul 21
• SemSpace2021
  Groningen University, Groeningen, NL
  Co-located with IWCS
  16 Jun 21
• Categories and Companions Symposium
  Macquarie University, Sydney, AUS
  8-12 Jun 21
• LGBTQ+MATH DAY
  Fields Institute, Toronto, CAN
  18 Nov 20
• Quantum Week of Fun
  Cambridge Quantum Computing, Oxford, ENG
  21 - 25 Sep 20
• SemSpace2020
  Utrecht University, Utrecht, NL
  Speaker
  6 - 7 Aug 20
• Applied Category Theory 2020
  MIT, Boston, US
  Keynote speaker
  5 - 10 Jul 20
• Topics in Category Theory: A Spring School
  Edinburgh University, Edinburgh, SCO
  11 - 13 Mar 20
• Logic and Structure in Computer Science and Beyond
  Leiden University, Leiden, NL
  9 - 13 Dec 19
• Applied Category Theory 2019 Adjoint School
  Oxford University, Oxford, ENG
  ~9 Feb - 26 Jul 19

Teaching, Tutoring and Outreach

• UCL

  (TA positions)
• Outreach in Nuffield Scheme , 25 July 2022
• Discrete Mathematics for Computer Scientists (COMP0147)
  Semester 1, 2021/22
• Computability and Complexity Theory (COMP0017)
  Semester 1, 2021/22
• Discrete Mathematics for Computer Scientists (COMP0147)
  Semester 1, 2020/21
• Logic and Database Theory (COMP0009)
  Semester 1, 2020/21
• Computability and Complexity Theory (COMP0017)
  Semester 1, 2020/21
• Discrete Mathematics for Computer Scientists (COMP0147)
  Semester 2, 2019/20
• Logic and Database Theory (COMP0009)
  Semester 1, 2019/20

Factoids

• I was awarded by the UCL Faculty of Engineering's 2022 Equality Diversity and Inclusion Awards with the motivation "LGBTQ+ advocate, raising visibility of queer computer scientists, delivered a talk at the LGBTQ+ STEM conference and had an EDI focus on research looking at language models."
• For my masters degree essay I wrote about algebraic deformation theory. Funnily enough, for a job interview I was asked to write a nontechnical 3 page summary of it which you can find here.
• I participated in an undergraduate research project supervised by Stephan Tilmann at Sydney University.The project was documented and presented to AMSI by Abdul Zreika
• I used to live in this very cool place.

Contact me by email at