The 2026 Prolog Improvement Propoals (PIPs) Workshop
You are invited to participate in the 2026 “Prolog Improvement Proposals (PIPs) Workshop”, to take place at ICLP 2026, as part of the Federated Logic Conference (FLoC) 2026, in Lisbon, Portugal, on July 19, 2026.
Preliminary Program (Saturday, July 19, 2026)
Times are local (Lisbon, Portugal) times.
12:30-14:00 • Lunch
14:00-14:10 • Welcome, introduction, and PIP progress report. Presenters: Manuel Hermenegildo and Theresa Swift
14:10-15:10 • Session 1:
15:10-15:50 • Coffee
15:50-16:30 • Session 2:
15:50-16:10 The Joys and (Mostly!) Frustrations of Relational Programming in Prolog: A miniKanren Perspective. Presenter: William Byrd
16:10-16:30 The mmin/mmax Table Modes in Picat. Presenter: Neng-Fa Zhou
16:30-17:10 • Panel: Using coding agents to help bring Prologs together. Presenters: Theresa Swift, José F. Morales, Jan Wielemaker, Carl Andersen. Moderator: Manuel Hermenegildo
17:10-17:15 • Closing.
What is a PIP
A PIP is a document describing the design and implementation of one Prolog language feature. Examples of PIPs that are recently completed or under development are the JANUS Python interface, static and dynamic dictionaries, JSON interface, modes, write term options, float enhancements, binary prefix operators, CSV interface, etc.
PIPs inform the Prolog user and developer community about existing approaches and provide implementers a reference for potential language standardization. It is acceptable to have PIPs describe alternative approaches to any given language feature, although it is hoped that PIPs will promote informal consensus over time. To this end, to be accepted, PIPs must be supported by at least two Prolog systems. This descriptive approach to standardization complements the existing prescriptive ISO framework and can serve as input to ISO deliberations. More information about the PIP framework and some initial PIPs is available here.
The workshop
This half-day workshop, held at ICLP 2026, as part of the Federated Logic Conference (FLoC) 2026, in Lisbon, Portugal, on July 19, 2026, will offer Prolog implementers and users a chance to discuss improvements to the Prolog language and the process of PIP creation. The workshop will begin with a review of the PIP process and of some recently developed PIPs. There will also be presentations from users and implementers of Prolog with short descriptions of features of systems that they believe would benefit other systems and that could evolve into a PIP. The idea is also to foster wide participation in the Prolog Improvements Forum activities so that new PIPs will be proposed, developed, reviewed, and adopted by the Prolog community at large.
In order to include as many implementers and interested users as possible we plan to conduct this as a hybrid conference.
The PIP Organizing Committee:
- Carl Andersen, RTX BBN Technologies
- Manuel Hermenegildo, U. Politécnica de Madrid and IMDEA Software Institute
- José F. Morales, U. Politécnica de Madrid and IMDEA Software Institute
- Joachim Schimpf, Coninfer Ltd, UK
- Theresa Swift, Johns Hopkins Applied Physics Lab
- David Warren, Stony Brook University
- Jan Wielemaker, Vrije Universiteit Amsterdam
