LMS-BCS-FACS Evening Seminar

De Morgan House, London, and online
Start date
Meeting Date
Peter Sewell (University of Cambridge)

Title: Underpinning mainstream engineering with mathematical semantics
Date: Thursday 18th November 2021
Venue: De Morgan House, London, and online

5:30 – 6:00pm: event opens.
6:00 – 7:00pm: talk from Professor Peter Sewell.
7:00 – 7:30pm: tea/coffee/biscuits.
8:00pm: end of event.

This is a hybrid event with availability for 20 people to attend in person at De Morgan House (57-58 Russell Square, London WC1B 4HS). It will also be available to watch via Zoom. The seminar is free of charge.

If you would like to attend the event in person, CLICK HERE.

If you would like to attend the event online via Zoom, CLICK HERE.

Email Katherine Wright, Society & Research Officer, if you have any questions: lmscomputerscience@lms.ac.uk.


Despite 80+ years of research on semantics and verification, mainstream computer systems and their engineering development processes remain almost entirely non-formal, reliant on ad hoc testing and prose specifications.  These have been good enough for industry to thrive, but their inability to exclude errors is one of the root causes of today's endemic security failures.

In this talk I'll discuss what it takes to put mathematically rigorous semantics to work for full-scale mainstream systems, touching on scientific, engineering, and social aspects, and on the benefits and costs.  This will draw on work with many colleagues on various key interfaces: processor architectures, programming languages, and network protocols; and on the CHERI and Morello projects, extending conventional architectures and languages with hardware support for capabilities, for fine-grained memory protection and encapsulation.

Taking mainstream engineering artifacts seriously also prompts new theory and tools, e.g. for the relaxed shared-memory concurrency semantics of real machines, quite different from traditional concurrency semantics, and for the semantics of C and of CHERI capabilities.


Peter Sewell is a Professor of Computer Science at the University of Cambridge.  His research aims to enable rigorous semantics-based engineering of mainstream systems, including real-world concurrency semantics, instruction-set semantics, and CHERI.  His PhD was with Robin Milner in Edinburgh.  He has held ERC AdG, EPSRC, and Royal Society research fellowships. With Watson, Moore, and Arm, he was one of the instigators of the UKRI Digital Security by Design programme, supporting development of the Arm Morello prototype CHERI Armv8-A architecture, processor, software, and semantics.