Gesetze sind Prosa, sie enthalten keine maschinenlesbare Semantik. (Laws are prose, they contain no machine readable semantics) And there was me hoping they had fixed that ! Ahwell, one step at a time :)
Rewriting law to be machine-readable as in "instructions a machine can understand" would be quite a task I suppose. Interesting project though. Would that even be possible? How well does the law map on the black and white logic of a computer?
There's a large area of legal philosophy around those kinds of questions. Pragmatism vs. formalism in judging is one split that's sometimes identified, with "formalism" being closer to a view that the law is a precise set of procedures that must be followed mechanically, and "pragmatism" closer to the view that the law is a set of principles that must be applied using common sense to reach equitable outcomes. Lots of other positions as well, around that "what is law, anyway" question.
There are some attempts to formalize something like the pragmatic view, too (oddly enough), in artificial intelligence "legal argumentation" systems, which try to model the back-and-forth of adversarial legal systems, determining when to bring up an argument, how to counter an argument, etc.