January 29 – February 3 , 2017, Dagstuhl Seminar 17051

Theory and Applications of Behavioural Types


Simon Gay (University of Glasgow, GB)
Vasco T. Vasconcelos (University of Lisbon, PT)
Philip Wadler (University of Edinburgh, GB)
Nobuko Yoshida (Imperial College London, GB)

For support, please contact

Dagstuhl Service Team


Dagstuhl Report, Volume 7, Issue 1 Dagstuhl Report
Aims & Scope
List of Participants
Dagstuhl's Impact: Documents available
Dagstuhl Seminar Schedule [pdf]


Behavioural types describe dynamic aspects of a program, in contrast to data types, which describe the fixed structure of data. Behavioural types include session types, typestate, choreographies, and behavioural contracts. Recent years have seen a substantial increase in research activity, including theoretical foundations, design and implementation of programming languages and tools, studies of the relationships between different forms of behavioural types, and studies of the relationships between behavioural types and more general type-theoretic ideas such as gradual typing and dependent typing. The aim of this seminar was to bring together researchers on behavioural types and related topics, in order to understand and advance the state of the art.

Many of the participants have been active in COST Action IC1201: Behavioural Types for Reliable Large-Scale Software Systems (BETTY), a European research network on behavioural types. Other participants were invited from related research areas and from outside Europe, in order to broaden the scope of the seminar and to make connections between communities.

The programme for the first half of the week was planned in advance, with priority given to two kinds of presentation: (1) demonstrations of programming language implementations and tools, and (2) presentations by participants from outside the BETTY community. The programme for the second half of the week evolved during the seminar, with more emphasis on group discussion sessions.

The seminar was judged to be a success by all the participants. At least one conference submission resulted from collaboration started during the week, other existing collaborations made substantial progress, and several participants planned a submission to the EU RISE funding scheme. We intend to propose a follow-on seminar on a similar topic in the future.

This report contains the abstracts of the talks and software demonstrations, and summaries of the group discussion sessions.

Summary text license
  Creative Commons BY 3.0 Unported license
  Simon Gay, Vasco T. Vasconcelos, Philip Wadler, and Nobuko Yoshida

Dagstuhl Seminar Series


  • Programming Languages / Compiler
  • Semantics / Formal Methods
  • Verification / Logic


  • Behavioural types
  • Session types
  • Typestate
  • Programming languages
  • Type systems
  • Semantics
  • Concurrency
  • Distributed systems
  • Static analysis
  • Runtime monitoring


In the series Dagstuhl Reports each Dagstuhl Seminar and Dagstuhl Perspectives Workshop is documented. The seminar organizers, in cooperation with the collector, prepare a report that includes contributions from the participants' talks together with a summary of the seminar.


Download overview leaflet (PDF).

Dagstuhl's Impact

Please inform us when a publication was published as a result from your seminar. These publications are listed in the category Dagstuhl's Impact and are presented on a special shelf on the ground floor of the library.


Furthermore, a comprehensive peer-reviewed collection of research papers can be published in the series Dagstuhl Follow-Ups.