Formalising a legal opinion on a legislative proposal in the ASPIC+ framework

This paper presents a case study in which an opinion of a legal scholar on a legislative proposal is formally reconstructed in the ASPIC(+) framework for argumentation-based inference. The reconstruction uses a version of the argument scheme for good and bad consequences that does not refer to single but to sets of consequences, in order to model aggregation of reasons for and against proposals. The case study is intended to contribute to a comparison between various formal frameworks for argumentation by providing a new benchmark example. It also aims to illustrate the usefulness of two features of ASPIC(+): its distinction between deductive and defeasible inference rules and its ability to express arbitrary preference orderings on arguments.