> The aim is not to formalise or put into code all the law, because that would make no sense, but we are interested in the law that is already executed automatically, such as the calculation of social benefits, tax or unemployment.

Can anyone explain why it's believed this "would make no sense"?

Law isn't written to cover 100% of real life scenarios and potential cases, it's written with deliberate parts of ambiguity, that will ultimately be up to courts to set the precedents for, in various situations and context.

I think the idea is that you can't really cover 100% of real-life cases in "code", either legal or software, so the areas you'll leave this out of would be those "not-entirely-strict" parts.

It does stand to reason that all law could be formalized. For example, consider the definition of murder in the first degree from 18 USC § 1111:

"Murder is the unlawful killing of a human being with malice aforethought."

You might say, well, "unlawful" and "malice" are fuzzy concepts; but we can take them to be facts that we input into the model. I guess we could write something like this in Catala:

    scope Murder :
      definition in_the_1st_degree
        under condition is_malice_aforethought and is_unlawful consequence
      equals
        true

However, in other areas of law, determining the facts is actually where the real work is -- was there malice aforethought? A formalized legal machine could process these facts but it's not a big help. The models would just be a huge list of assumptions that have to be input and a minimal calculation that produces `true` or one of the alternatives of an enum.

A computer program takes digital bytes, runs some discrete logic on them, outputs some more bytes. Laws take messy real world stuff, run some subjective decision tree on them, and output some messy real world actions to take. If you model the former with the latter you end up 'shelling out' to human judgement every 2 words. Suppose you accidentally shoot somebody while duck hunting, the meaning or value of pretty much everything here can't be determined by a computer, so the code-law version of this random snippet of natural-language-law would be pretty useless:

> If it is found that the defendant did the killing or wounding, but that it was not intentional or negligent, the court shall dismiss the proceeding. Otherwise, if it is found that the defendant did the killing or wounding intentionally, by an act of gross negligence, or while under the influence of alcohol, the court shall issue an order permanently prohibiting the defendant from taking any bird or mammal.

A lot of law is based around subjective gray lines. “How would a reasonable person behave in this unique situation?” Is at the root of a lot of legal situations.

Write a function for that, keeping in mind that “this situation” needs to be modeled with potentially infinite variables. Then try to define a “reasonable person”.

Hell, the reason most trials happen is because there is huge grey area, and the written laws are not obvious as to what the outcome should be.

Commercial law nuts and bolts is very algorithmic often.

Criminal law is often fundamentally subjective, incorporating questions of intent and remorse.

I assume it would fail to compile, or error out, because of myriad conflicts throughout the body of laws.

I think the primary reason is that laws are about human convention, not real objects which one can clearly and deliberately define. Like at the most basic level nothing exists at all except for quantum fields or something like that. Everything else we talk about on a regular basis, people, dogs, streets, businesses, etc, is defined by convention to a greater or lesser degree.

It is therefore quite hard to create a formal system to refer to objects in the world in a way which induces no contradictions with intuition. This is why we have courts, among other functions of government.

Basically, all human knowledge is an application of either math or philosophy, and law is philosophy, so cant be modeled by math