Uploaded September 2026 | Updated September 2026, 2 weeks ago
Topos Institute Colloquium, 3rd of September 2026.
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The philosophical tradition of 'analytic pragmatism' attempts to account for linguistic meanings in terms of their practices of use. In particular, 'logical expressivism' is a theory which offers a distinct perspective on logic, one which inverts the traditional picture of logical calculi regulating how to derive new judgments from assumed ones. Instead, we start with all judgments in some vocabulary arbitrarily marked as good or bad (taken as raw, input data), and from that we conservatively extend the vocabulary with logical connectives which play the role of expressing (or internalizing) features of the raw input judgment data. This talk sheds light on a recent formalization of logical expressivism (Brandom and Hlobil 2024) by reconstructing its formal semantics through the use of universal constructions, in particular an adjunction which freely adds the structure of Girard quantales to the pragmatic input data, which itself can be viewed as a radically-substructural logic.
Slides: krisb.org/docs/slides/toposcolloq
Topos Institute Colloquium, 3rd of September 2026.
———
The philosophical tradition of 'analytic pragmatism' attempts to account for linguistic meanings in terms of their practices of use. In particular, 'logical expressivism' is a theory which offers a distinct perspective on logic, one which inverts the traditional picture of logical calculi regulating how to derive new judgments from assumed ones. Instead, we start with all judgments in some vocabulary arbitrarily marked as good or bad (taken as raw, input data), and from that we conservatively extend the vocabulary with logical connectives which play the role of expressing (or internalizing) features of the raw input judgment data. This talk sheds light on a recent formalization of logical expressivism (Brandom and Hlobil 2024) by reconstructing its formal semantics through the use of universal constructions, in particular an adjunction which freely adds the structure of Girard quantales to the pragmatic input data, which itself can be viewed as a radically-substructural logic.
Slides: krisb.org/docs/slides/toposcolloq
![[DOTS Lectures] 4. Composing Moore Machines](https://i.ytimg.com/vi/jsM2jTuT_Zc/mqdefault.jpg "[DOTS Lectures] 4. Composing Moore Machines
Part of a lecture series on the Double Operadic Theory of Systems (DOTS) presented by David Jaz Myers.")
![[2-torial] David Jaz tells Brendan about a topos-theoretic interpretation for conceptual modelling](https://i.ytimg.com/vi/kFQpKp-ehZI/mqdefault.jpg "[2-torial] David Jaz tells Brendan about a topos-theoretic interpretation for conceptual modelling
Recorded at the Oxford Office on the 5th of December 2025.")
![[DOTS Lectures] 1. Categories of systems](https://i.ytimg.com/vi/kZ4muU5Wc_4/mqdefault.jpg "[DOTS Lectures] 1. Categories of systems
Part of a lecture series on the Double Operadic Theory of Systems (DOTS) presented by David Jaz Myers.")
![[Berkeley Seminar] Raph Levien | How Rust won: the quest for performant, reliable software](https://i.ytimg.com/vi/k_-6KI3m31M/mqdefault.jpg "[Berkeley Seminar] Raph Levien | How Rust won: the quest for performant, reliable software
Title: How Rust won: the quest for performant, reliable software
Abstract: For a long time, high performance has been in tension with reliability. In particular, languages designed for high performance were not memory safe, with real implications for unexpected crashes and security vulnerabilities. Rust is the first practical language to address this tension, building on affine types and other principles programming language theory, synthesized with an attention to low level systems programming. Rust’s success emerged not just from a clever idea, but consistently excellent execution and the formation of a strong community around the language. This talk will discuss several aspects of what Rust got right, as well as the rocky journey of ideas from academic theory to real world impact.
Slides: https://docs.google.com/presentation/d/1SoDsm_m_pb_gS6Y98HghhzBviYZxp3F2XawhIppJQQo/edit?usp=sharing
https://topos.institute/events/berkeley-seminar/")
![[DOTS Lectures] 11. A general representability theorem for Systems Theory Pt. 1](https://i.ytimg.com/vi/kpmhI1oHGnM/mqdefault.jpg "[DOTS Lectures] 11. A general representability theorem for Systems Theory Pt. 1
Part of a lecture series on the Double Operadic Theory of Systems (DOTS) presented by David Jaz Myers.
Some material from these lectures can be found in Davids book on categorical systems theory:
https://www.davidjaz.com/Papers/DynamicalBook.pdf")
![[TopOx] Steve Awodey: Path Types in Algebraic Type Theory](https://i.ytimg.com/vi/lanvZuki4qQ/mqdefault.jpg "[TopOx] Steve Awodey: Path Types in Algebraic Type Theory
18th of May 2026. Slides available at https://topos.institute/events/topox/
A representable natural transformation u : U* → U in the category Psh(C) of presheaves on a small category C is a “natural model of dependent type theory. The type-forming operations may be described as an algebraic structure on u, representing corresponding operations on the type-families classified by u. For example, the dependent product or “Pi-type” is an algebra structure for the polynomial endofunctor
P_u : Psh(C) → Psh(C) .
Similar operations on u represent the other type-formers of unit type, dependent sums, and identity types. The latter are given by a recently determined “path-type” structure, which relates such models to cubical (Quillen) model categories.")
![[DOTS Lectures] 17. Representability for double operad algebras](https://i.ytimg.com/vi/larbRprPuPM/mqdefault.jpg "[DOTS Lectures] 17. Representability for double operad algebras
Part of a lecture series on the Double Operadic Theory of Systems (DOTS) presented by David Jaz Myers.
Some material from these lectures can be found in Davids book on categorical systems theory:
https://www.davidjaz.com/Papers/DynamicalBook.pdf")
