2024-12 Report

In the following, we are describing our current vision for the development of the <...> tool. The features we describe will be developed to different degrees of polish, and most of them are as of now in the middle of active development. This is why we are only including descriptions, and sometimes (mockup) screenshots, in our current report.

On the other hand, we are only including in the current report the parts that we have started actively working on. Some other features of the proposal are being left to later. (TODO: check validity of this statement, make it more concrete)

The tool we are planning to build is centered around a two-window view:

• On the left, we edit legislation using a domain-specific language. This language is called JL4 (for Jersey-L4) and is a variant of the L4 line of languages previously developed by SMU CCLAW.

  The language is reminiscent of natural language, but follows rigid rules and has clear and unambiguous semantics.

• On the right, we can obtain various other views of (parts of) the legislation text open on the left. In particular, we aim for:

  • A natural language representation; while still stilted in nature, this version should nevertheless read as plain English and be understandable to an untrained reader.

  • A visualisation of the Boolean decision logic encoded in the legislation as an interactive "ladder circuit diagram".

  • A visualisation of the Boolean decision logic encoded in the legislation as a questionnaire.

• We are planning to add more information views at later stages, in particular:

  • A visualisation of the state transition system encoded in the legislation as an automaton.

In the following, we are describing each of these views and visualisations in more detail.

1K Words

https://docs.google.com/drawings/d/1CaJtpHDnRPQAfC2q3jdXjuXObJu9fN2WrJNfuqawHOk/edit

These deliverables come from https://docs.google.com/document/d/1hPuBnqTcGm5gicwo06m68GqsP_YSUn8VoZfd7-cbcfI/edit?tab=t.0

[ d
| d <- deliverables
, deadline d ~= "Dec 2024"
]

JL4 window

The contents of the left window are essentially programs in a (domain-specific) programming language, but we try our best to make such programs pleasant to read to a relatively untrained eye, and to make the language keywords and concepts reminiscent of words a legal drafter would be using and attaches meaning to.

In programming language terms, the language features the following concepts:

• A syntax that uses plain English keywords and avoids the use of symbols and parentheses in many places in favour of descriptive words and layout.

• A way to declare new concepts (corresponding to datatypes in a programming language). In particular, concepts can be enumerations and records.

• A way to define new values. Values can be Boolean, numeric (including e.g. monetary amounts), and can be elements of the previously mentioned user-defined concepts. Values can be parameterised, i.e., they can depend on other inputs that are part of the overall situation.

In a second iteration, the language also features:

• A way to define parties as well as obligations or prohibitions that apply to a particular party.

There are further features of the JL4 language:

• Any concept or value can be annotated with natural language phrases that explain them further and which will be used in the natural language view.

• Whenever a concept or value is referred to, the tool will check where it is being defined, and allow to display information about the location of definition and the kind of definition it is by hovering over the identifier.

• If a concept or a value is mentioned without having a definition, this will be highlighted as an error.

• If a concept or a value is used in a way that doesn't match the nature of its definition, this will also be highlighted as an error. (TODO: needs an example).

TODO: snippets / refactorings?

TODO: error messages?

Visualisation window

As described above, the right window of the tool will be able to display various pieces of additional information about the contents of the left window. This information can be requested by clicking on particular buttons in the user interface.

As an approximation, the right window is informational, i.e., while some of the visualisations are interactive, the results of such interactions do not affect the contents of the left window.

In the more distant future, it is conceivable that this interactivity of the visualisations is expanded on, and that we will allow changes to the visualisations to be made that result in changes to the program.

Natural language view

Ladder circuit diagrams

Questionnaires

Transition systems

...