The 2025 Prolog Improvement Propoals (PIPs) Workshop

You are invited to participate in the 2025 “Prolog Improvement Proposals (PIPs) Workshop”, to take place at ICLP 2025, U. of Calabria in Rende, Italy.

Preliminary Program (Friday, September 12, 2025)

Location: DEMACS, Cubo 30B, Room MT12

Times are local (Rende, Italy) times.

• 16:30-17:00 • Coffee break

• 17:00-17:15 • Welcome, Introduction, and Progress Report. Presenter: Manuel Hermenegildo

• 17:50-17:15 • PIP presentations and discussions

  • 17:15-17:35 PIP-0102: Dictionaries in Prolog (dynamic). Presenter: Jan Wielemaker

  • 17:35-17:55 PIP-0104: Terms with named arguments (static dicts). Presenter: José Francisco Morales

  • 17:55-18:15 PIP-0103: Modes and their precise meaning. Presenter: Manuel Hermenegildo

  • 18:15-18:35 PIP-0105: Options in write_term. Presenter: Jan Wielemaker

  • 18:35-18:45 PIP-0100: JSON to and from Prolog. Presenter: Theresa Swift

• 18:45-19:20 • General discussion. Moderator: Theresa Swift

• 19:20-19:30 • Wrapup and plans. Chair: José Francisco Morales

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, a JSON interface specification, a specification for modes, write term options, etc.

PIPs inform the Prolog community about existing approaches and also 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 will complement the existing prescriptive ISO framework and may 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 2025 in Rende, Italy in September, will offer Prolog implementers and users a chance to understand and comment on the process of PIP creation so that they can adapt it to their own interests. The workshop will begin with a review of the current PIP process and of recently developed PIPs. Next, there will be a chance for implementers and users of Prologs to present short descriptions of features of systems that they believe would benefit other systems. We hope that a result of this workshop will be a wider use of the new Prolog Implementers Forum 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 PIP25 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

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The Prolog Implementers Forum is a part of the "All Things Prolog" online Prolog community, an initiative of the Association for Logic Programming stemming from the Year of Prolog activities.