Argumentation in Legal Reasoning

We will review systems that can store conflicting interpretations and that can propose alternative solutions to a case based on these interpretations. We will also describe systems that can use legal precedents to generate arguments by drawing analogies to or distinguishing precedents. We will discuss systems that can argue why a rule should not be applied to a case even though all its conditions are met. Then there are systems that can act as a mediator between disputing parties by structuring and recording their arguments and responses. Finally we look at systems that suggest mechanisms and tactics for forming arguments. Much of the work described here is still research: the implemented systems are prototypes rather than finished systems, and much work has not yet reached the stage of a computer program but is stated as a formal theory. Our aim is therefore to give a flavour (certainly not a complete survey) of the variety of research that is going on and the applications that might result in the not too distant future. Also for this reason we will informally paraphrase example inputs and outputs of systems rather than displaying them in their actual, machine-readable format; moreover, because of space limitations the examples have to be kept simple.