Category Archives: PIDE

Isabelle/VSCode and the Language Server Protocol at Curry Club Augsburg

Here is the video for my presentation at Curry Club Augsburg (09-Aug-2018) about Isabelle/VSCode and the Language Server Protocol:

The PDF Slides (including important links) are also available.

Video for Isabelle/PIDE presentation at Curry Club Augsburg

Here is the video for the Isabelle/PIDE presentation at Curry Club Augsburg from 14-Jun-2018:

There are some technical challenges: missing screen recording in the first 25min, and occasional changes in the speed of screen recording later on: sometimes the computer screen is ahead of the talk. Nonetheless, this is an opportunity to learn many things about Isabelle/PIDE, how it is done, why it is done like that.

Isabelle/jEdit as Formal IDE at Curry Club Augsburg

On Thu 14-Jun-2018 I will talk about Isabelle/jEdit as Formal IDE at Curry Club Augsburg.

Start: approximately 19:00.
Duration: undefined.
Language of the talk: German
Slides: PDF

This is a spin-off from the paper that I will present at the F-IDE workshop on Sat 14-Jul-2018 in Oxford.

Isabelle/jEdit as formal IDE

This is my contribution to the F-IDE workshop (14-Jul-2018, Oxford, UK): Isabelle/jEdit as IDE for domain-specific formal languages and informal text documents.


Isabelle/jEdit is the main application of the Prover IDE (PIDE) framework and the default user-interface of Isabelle, but it is not limited to theorem proving. This paper explores possibilities to use it as a general IDE for formal languages that are defined in user-space, and embedded into informal text documents. It covers overall document structure with auxiliary files and document antiquotations, formal text delimiters and markers for interpretation (via control symbols). The ultimate question behind this: How far can we stretch a plain text editor like jEdit in order to support semantic text processing, with support by the underlying PIDE framework?

The Isabelle Server: responsive control of prover sessions

Recent Isabelle repository versions (e.g. 83902fff6243 as approximation of Isabelle2018) support client-server connections for Isabelle prover sessions, with a
simple line-based protocol for synchronous commands. Asynchronous tasks work by explicit indication of forked vs. finished (or failed) background processes, potentially with intermediate notifications. Protocol messages use JSON syntax by default, but YXML is also possible (e.g. for native PIDE messages that might be supported in the future).

Further details are explained in chapter 4 of the system manual, e.g. see the Documentation panel in Isabelle/jEdit of a recent release snapshot. Here is a minimal example extracted from the manual:

isabelle server &
isabelle client
session_start {"session": "HOL"}
use_theories {"session_id": ..., "theories": ["~~/src/HOL/ex/Seq"]}
session_stop {"session_id": ...}

The first two commands are for the Unix terminal, the rest for the Isabelle client-server loop. Each line needs to be applied carefully, when the previous command has finished, and use_theories needs to fit on a single line.

Under program control, explicit messages for forked and finished tasks (with unique id) may be used to enforce execution in the proper order.

Update 12-Jul-2018: Link to forthcoming Isabelle2018.

Scaling Isabelle Proof Document Processing

Isabelle applications (e.g. from AFP) are growing steadily in size and number. To outline requirements and possibilities of the technology, I have produced a document on Scaling Isabelle Proof Document Processing.


This is a study of performance requirements, technological side-conditions, and possibilities for scaling of formal proof document processing in Isabelle and The Archive of Formal Proofs (AFP). The approaches range from simple changes of system parameters and basic system programming with standard APIs to more ambitious reforms of Isabelle and the underlying Poly/ML system. The running examples for typical scalability issues are existing formalizations of classical analysis and differential equations. Such applications can be further extrapolated towards a development of Financial Mathematics (e.g. Itô calculus).

Future Prospects of Isabelle Technology

On 23-Nov-2017, I will give a presentation about Future Prospects of Isabelle Technology at DTU (Danmarks Tekniske Universitet), Copenhagen – thanks to an invitation by Jørgen Villadsen. More information on the meeting is available on the website.


In the past 3 decades, Isabelle has made a long way from a modest LCF-style proof assistant (with copy-paste of proof scripts written in ML) to the current Isabelle/PIDE editor-environment (with its timeless and stateless processing of proof documents). In this presentation, I will try to extrapolate this into the future: How far can we scale proof documents and libraries, e.g. via moving Isabelle into the “cloud”? How can we reduce system resource requirements on the client side? How can we upgrade interactive edits produced by a single author, towards versioned changesets by multiple or distributed authors? What are suitable frameworks for the next generation of Isabelle document preparation? What can we make out of Isabelle/ML as ultra-clean environment for functional programming? Etc. etc.

Sources for the presentation: Copenhagen2017.tar.gz

Isabelle/VSCode 1.0 in Isabelle2017

The new Isabelle2017 release includes support for VSCode as alternative Prover IDE front-end. This continues earlier experiments and is released as Isabelle/VSCode 1.0. Note that Isabelle/jEdit had its 1.0 release in October 2011 and is presently at version 9.0.

Isabelle2017 provides the main Isabelle/Scala/PIDE functionality to connect to VSCode, using the official Language Server Protocol (with some PIDE add-ons). The front-end requires the extension called “Isabelle2017” from the VSCode marketplace: its README provides more information and installation instructions.

The Isabelle/VSCode project has been made possible thanks to funding by Aesthetic Integration (Grant Passmore and Denis Ignatovich).

The Isabelle Prover IDE after 9 years of development, and beyond

On Mon 24-Jul-2017, I gave a presentation at the BigProof event in Cambridge. Title: The Isabelle Prover IDE (PIDE) after 9 years of development, and beyond. Abstract:

The main ideas around Isabelle/PIDE go back to summer 2008. This is an overview of what has been achieved in the past 9 years, with some prospects for the future. Where can we go from here as Isabelle community? (E.g. towards alternative front-ends like Visual Studio Code; remote prover sessions “in the cloud”; support for collaborative editing of large formal libraries.) Where can we go as greater ITP community (Lean, Coq, HOL family)?

Here are some notable VSCode projects that were briefly mentioned in the talk:

Visual Studio Code as Prover IDE for Isabelle

Microsoft is more and more becoming an Open Source company, e.g. it has joined the Linux foundation as Platinum member in November 2016. A notable Open Source project by Microsoft is Visual Studio Code: under the slogans “Code editing. Redefined. Free. Open Source. Runs everywhere.” it provides a very interesting editor framework, as a desktop application based on Node.js and TypeScript.

The prover community has already started to support this emerging successor of vi and Emacs, e.g. see Coq Support for Visual Studio Code and the Lean for VSCode.

Isabelle/VSCode is now following this trend: I have spent some weeks in December 2016 / January 2017 with VSCode, using a little bit of TypeScript and implementing the new Language Server Protocol in Isabelle/Scala. The subsequent screenshot shows formal annotations produced by Isabelle/PIDE in the usual manner, while the editor rendering is all done by VSCode. For more information, see the report Isabelle/VSCode in January 2017.

The Isabelle/VSCode project was funded by Aesthetic Integration (AI). See also my article about a talk at ITP 2016 by Grant Passmore (co-founder of AI).