The two main types of law are legislation and precedents. Both types have a corresponding reasoning pattern determining legal consequences: legislation can be applied and precedents followed. The separate modelling of these two reasoning patterns using logical techniques has recently seen considerable progress. About the logical links between the two less is known, although progress has already been made. This document focuses on such logical relations. The main question is: to what extent can the application of legislation and precedent adherence be considered as two sides of the same logical coin? Findings from the boundaries of logic and law will serve as a starting point.

This text is a translated, adapted and extended version of Verheij 2007.