FL, A Legal Drafting Language Based on Models

Humans have faced the need to formalize, among others, two types of prescriptive behaviors. On one hand there is Law, whose formalization is being suggested at least from 1926, and on the other hand there are software specifications. The formal treatment of the later can be considered successful, in the sense that plenty of methods and tools exist that allow to specify the behavior of quite complex pieces of software, and to check those specifications for errors and omissions. Law has seen many formalization attempts from the area known as deontic logic. Nevertheless, these approaches usually have some problems related to expressiveness limitations and “paradoxes”. In this article we present the design rationale for FL, an LTL-based language targeted at operational regulations that can solve many of the problems of traditional deontic approaches while at the same time providing tool support to check for incoherence and related problems.