From emma.tye at strath.ac.uk Tue May 5 11:02:10 2026 From: emma.tye at strath.ac.uk (=?utf-8?Q?Emma_Tye?=) Date: Tue, 05 May 2026 10:02:10 +0000 Subject: [msp-interest] [MSP101] Bob Atkey: Embedding containers in coherence spaces (3pm Thu 7/5, LT711) Message-ID: Dear all, We have another MSP101 seminar coming up. Hope to see you there! Best wishes, Emma Date, time and place: Thursday 7 May, 15:00, Livingstone Tower room LT711 Online attendance: https://www.youtube.com/channel/UC3IBMh699qT5wawP3nHRItg/live Speaker: Bob Atkey (MSP) Title: Embedding containers in coherence spaces Abstract: Containers are a representation of polynomial functors that have been used variously for describing data types and for back-and-forth communication, amongst other things. Coherence spaces are a model of classical linear logic, as well as a special kind of Scott domain. I will describe a functor from the category of containers into coherence spaces and linear maps. This functor is faithful, and is full if we allow partial maps of containers. MSP101 Feeds: Web: http://msp.cis.strath.ac.uk/msp101.html RSS: http://msp.cis.strath.ac.uk/msp101.rss iCal: http://msp.cis.strath.ac.uk/msp101.ics From emma.tye at strath.ac.uk Fri May 8 12:15:12 2026 From: emma.tye at strath.ac.uk (=?utf-8?Q?Emma_Tye?=) Date: Fri, 08 May 2026 11:15:12 +0000 Subject: [msp-interest] [MSP101] Fredrik Nordvall Forsberg: Constructive transfinite constructions (3pm Thu 14/5, LT711) Message-ID: Dear all, We have another MSP101 seminar coming up. Hope to see you there! Best wishes, Emma Date, time and place: Thursday 14 May, 15:00, Livingstone Tower room LT711 Online attendance: https://www.youtube.com/channel/UC3IBMh699qT5wawP3nHRItg/live Speaker: Fredrik Nordvall Forsberg (MSP) Title: Constructive transfinite constructions Abstract: Based on a talk by Benno van den Berg at TYPES the week before this talk, I will try to understand how transfinite constructions, such constructing the initial algebra of a functor as the colimit of its initial chain, can be carried out in a constructive metatheory. I will discuss what notion of ordinal Benno says is suitable for this. MSP101 Feeds: Web: http://msp.cis.strath.ac.uk/msp101.html RSS: http://msp.cis.strath.ac.uk/msp101.rss iCal: http://msp.cis.strath.ac.uk/msp101.ics From emma.tye at strath.ac.uk Fri May 15 11:45:46 2026 From: emma.tye at strath.ac.uk (=?utf-8?Q?Emma_Tye?=) Date: Fri, 15 May 2026 10:45:46 +0000 Subject: [msp-interest] [MSP101] Emma Tye: A Rig of Transformations (1pm Thu 21/5, LT711) Message-ID: Dear all, We have another MSP101 seminar coming up. Hope to see you there! Best wishes, Emma Date, time and place: Thursday 21 May, 13:00, Livingstone Tower room LT711 Online attendance: https://www.youtube.com/channel/UC3IBMh699qT5wawP3nHRItg/live Speaker: Emma Tye (MSP) Title: A Rig of Transformations Abstract: Describing (binary) data representatations and transformations for types can be tricky to do correctly, efficiently and erganomically. I will show what I have been working on - modelling algebraic data types as a "rig" (ring without "n"egation), where the equalities are treated as bi-directional transformations (isomorphisms) between data. Using this approach, we can also model inclusions of one data type into another as a "partial" isomorphism, allowing for padding of data. Furthermore, we can ask how (partial) isomorphisms interact with functions on data types - with some surprising answers! MSP101 Feeds: Web: http://msp.cis.strath.ac.uk/msp101.html RSS: http://msp.cis.strath.ac.uk/msp101.rss iCal: http://msp.cis.strath.ac.uk/msp101.ics From emma.tye at strath.ac.uk Fri May 22 11:34:00 2026 From: emma.tye at strath.ac.uk (=?utf-8?Q?Emma_Tye?=) Date: Fri, 22 May 2026 10:34:00 +0000 Subject: [msp-interest] [MSP101] Rin Liu: ilsts (Symmetric List Objects) (1pm Thu 28/5, LT711) Message-ID: Dear all, We have another MSP101 seminar coming up. Hope to see you there! Best wishes, Emma Date, time and place: Thursday 28 May, 13:00, Livingstone Tower room LT711 Online attendance: https://www.youtube.com/channel/UC3IBMh699qT5wawP3nHRItg/live Speaker: Rin Liu (MSP) Title: ilsts (Symmetric List Objects) Abstract: Cons-lists are fundamental to functional programming, and are often constructed as inductive types or initial algebras. More generally, lists can be axiomatised internally in any monoidal category as list objects, without requiring sums or existence of initial algebras. When strengthened to parametrised list objects, they give a construction of free monoids. In monoidal categories with symmetry, we can consider symmetric variants of these definitions -- symmetric list objects or ilsts -- that allow transposing the two front elements of the list. We will show string-diagramatically that these give a construction of the free commutative monoid, and then show some properties of related objects. MSP101 Feeds: Web: http://msp.cis.strath.ac.uk/msp101.html RSS: http://msp.cis.strath.ac.uk/msp101.rss iCal: http://msp.cis.strath.ac.uk/msp101.ics