[6]: 386 One of the first use cases was the encoding of the British Nationality Act at Imperial College carried out under the supervision of Marek Sergot and Robert Kowalski.
Lance Elliot wrote: "The British Nationality Act was passed in 1981 and shortly thereafter was used as a means of showcasing the efficacy of using Artificial Intelligence (AI) techniques and technologies, doing so to explore how the at-the-time newly enacted statutory law might be encoded into a computerized logic-based formalization."
[7] The authors’ seminal article, "The British Nationality Act as a Logic Program," published in 1986 in the Communications of the ACM journal, is one of the first and best-known works in computational law, and one of the most widely cited papers in the field.
[8] In 2021, the Inaugural CodeX Prize was awarded to Robert Kowalski, Fariba Sadri, and Marek Sergot in acknowledgment of their groundbreaking work on the application of logic programming to the formalization and analysis of the British Nationality Act.
[12] This expert system model is capable of recognizing and classifying patterns within the realm of legal knowledge and dealing with imprecise inputs.
[14]: 18 Fuzzy logic models attempt to create 'fuzzy' concepts or objects that can then be converted into quantitative terms or rules that are indexed and retrieved by the system.
[15] Some legal expert system architects have adopted a very practical approach, employing scientific modes of reasoning within a given set of rules or cases.
The consequence of this approach is the creation of narrowly focused and geographically restricted legal expert systems that are difficult to justify on a cost-benefit basis.
[19] ASHSD-II is a hybrid legal expert system that blends rule-based and case-based reasoning models in the area of matrimonial property disputes under English law.
[23] Split-Up is a rule-based legal expert system that assists in the division of marital assets according to the (Australia) Family Law Act (1975).
[21] TAXMAN is a rule-based system that could perform a basic form of legal reasoning by classifying cases under a particular category of statutory rules in the area of law concerning corporate reorganization.
[25]: 837 Catala is a French domain-specific programming language designed for deriving correct-by-construction (as assured by formal methods) implementations from legislative texts.
In its article entitled 'No Code and Lawyers', the NoCode Journal[30] mentions tools such as Neota Logic, VisiRule, Berkeley Bridge, BRYTER and Josef as all being used within the legal sector for a variety of purposes including Self-Service Legal and Policy Advice, Document Drafting, Document Automation, New Business Intake and Analysis, Expert Decisioning, Business Process Automation and other use cases.