LFMTP 2025

July 19, Birmingham, UK, associated with FSCD at FSCD 2025

Scope

Logical frameworks and meta-languages form a common substrate for representing, implementing and reasoning about a wide variety of deductive systems of interest in logic and computer science. Their design, implementation and their use in reasoning tasks, ranging from the correctness of software to the properties of formal systems, have been the focus of considerable research over the last two decades. This workshop will bring together designers, implementors and practitioners to discuss various aspects impinging on the structure and utility of logical frameworks, including the treatment of variable binding, inductive and co-inductive reasoning techniques and the expressiveness and lucidity of the reasoning process.

LFMTP 2025 will provide researchers a forum to present state-of-the-art techniques and discuss progress in areas such as the following:

• Encoding and reasoning about the meta-theory of programming languages, logical systems and related formally specified systems.

• Theoretical and practical issues concerning the treatment of variable binding, especially the representation of, and reasoning about, datatypes defined from binding signatures.

• Logical treatments of inductive and co-inductive definitions and associated reasoning techniques, including inductive types of higher dimension in homotopy type theory

• Graphical languages for building proofs, applications in geometry, equational reasoning and category theory.

• New theory contributions: canonical and substructural frameworks, contextual frameworks, proof-theoretic foundations supporting binders, functional programming over logical frameworks, homotopy and cubical type theory.

• Applications of logical frameworks: proof-carrying architectures, proof exchange and transformation, program refactoring, etc.

• Techniques for programming with binders in functional programming languages such as Haskell, OCaml or Agda, and logic programming languages such as lambda Prolog or Alpha-Prolog.

The workshop’s program will include contributed and invited talks.

Proceedings

A selection of the presented papers will be published online in the Electronic Proceedings in Theoretical Computer Science (EPTCS).

Invited Speakers

• Sonia Marin, University of Birmingham

  Intuitionistic modalities through proof theory

  Intuitionistic modal logic, despite more than seventy years of investigation, still partly escapes our comprehension. Structural proof theoretic accounts of intuitionistic modal logic have adopted either the paradigm of labelled deduction in the form of labelled natural deduction and sequent systems, or the one of unlabelled deduction in the form of sequent or nested sequent systems. Both approaches are still under active consideration. In this talk, I would like to give an overview of the current landscape of intuitionistic modal proof theory and survey some of the more recent developments.

• Yannick Forster, Inria Paris

  Obtaining executable programs from dependently typed proof assistants

  Proof assistants based on dependent type theory are also powerful programming languages. Different proof assistants such as Rocq, Lean, and Agda make different design decisions how to obtain executables for programs, which is relevant for type checking and computation-heavy proof techniques.

  Rocq’s type theory has been designed almost from its conception with extraction of idiomatic OCaml programs in mind. The OCaml compiler can then be used to obtain executables for Rocq programs. Haskell and Scheme are also supported as target languages, and more recently C, Rust, Wasm, and other languages. At the core of extraction is a type and proof erasure procedure due to Christine Paulin-Mohring and Pierre Letouzey, while typing in the target languages has to rely on unsafe casts. Optionally, elements of types can be extracted to more efficient runtime representations, using e.g. bignum for natural numbers.

  Lean uses the same foundations and the same type and proof erasure procedure as Rocq, but makes the radical decision to implement its own optimising compiler down to C, since recently bootstrapped as a Lean program. By default, some elements of types are compiled to more efficient runtime representations, using e.g. GMP for natural numbers.

  Agda allows program extraction to Haskell, where to be erased proofs have to be annotated manually.

  In this invited talk, I survey these and other approaches discussing verifiability and trusted computing bases, maintenance overhead, performance, and future directions, as well as the ability to internally reason about what programs can exist.

Program

Accepted Papers

• Zhibo Chen and Frank Pfenning. “CoLF Logic Programming as Infinitary Proof Exploration”
• Nathan Guermond and Gopalan Nadathur. “Ground Stratification for a Logic of Definitions with Induction”
• Ambrus Kaposi and Szumi Xie. “Type theory with single substitutions”
• Maribel Fernández, Miguel Pagano, Nora Szasz and Álvaro Tasistro. “Dependently Sorted Nominal Signatures”
• Thorsten Altenkirch, Nathaniel Burke and Philip Wadler. “Substitution without copy and paste”
• Sebastian Urciuoli. “On the Formal Metatheory of the Pure Type System using One-sorted Variable Names and Multiple Substitutions”

Program Committee

• David Baelde (ENS Rennes, IRISA)
• Kaustuv Chaudhuri, Co-Chair (Inria)
• Thaynara A. de Lima (IME, Federal University Goiás, Brazil)
• Temur Kutsia (RISC, Johannes Kepler University Linz, Austria)
• Marina Lenisa (University of Udine)
• Chris Martens (Northeastern University, USA)
• Daniele Nantes-Sobrinho, Co-Chair (Imperial College London)
• Giselle Reis (CMU, Qatar)
• Daniel Ventura (INF, Federal University Goiás, Brazil)

Important Dates

• Abstract submission deadline: May 2 May 9
• Paper submission deadline: May 9 May 16
• Notification to authors: June 6 June 8

All deadlines are AoE (anywhere on earth)

Submission Call for Papers

Submissions are now closed!

Submit on EasyChair: https://easychair.org/conferences?conf=lfmtp2025

In addition to regular papers, we welcome/encourage the submission of “work in progress” reports, in a broad sense. Those do not need to report fully polished research results, but should be of interest for the community at large.

Submitted papers should be in PDF, formatted using the EPTCS style guidelines. The length is restricted to 15 pages for regular papers and 8 pages for “Work in Progress” papers.