> If there is later a disagreement about what was agreed to, a judge sorts it out.
Only because human language leaves a lot of room for interpretation. Computer output doesn't, or at the very least not nearly to the same extent. If your smart contract is itself legal (you are legally allowed to formalize those terms), and produced an output as a function of it's actual internal operation (and not a random, accidental bit flip) then it should stand even in front of a judge.
I don't know what a smart contract is, but seems to me that if you can convicingly argue that the function output is inconsistent with what the parties agreed to, it would not stand.
There are contract disputes all the time over what a word or phrase means, and what a judge will look at is which interpretation best aligns with the broad strokes of what the parties were agreeing to. Nobody agrees to a contract that contains "I get to void the entire agreement at my discretion, keep the proceeds, and leave you with nothing"
> if you can convicingly argue that the function output is inconsistent with what the parties agreed to
Talking about (smart) contracts in general, if both parties agree that there was an error they can resolve it without any court. The problem is when only one party disagrees.
Imagine you have a contract with the bank and agree to pay 10% interest on a loan. Later on you try to claim you just weren't paying attention and thought it's 1.0%. That's a hell of a case to prove in front of a judge. And if that were the case the concept of contract would be worthless, invalidated by simply claiming "I didn't mean that".
A smart-contract should be easily reproducible. If that piece of code consistently returns the same result under the specified conditions then it's valid even if the result was because of a mistake the author made while preparing it.
> Only because human language leaves a lot of room for interpretation
Technically no. Many things have intrinsic physical value that cannot be tracked via digital contracts. If I go to amazon and buy a book, but they ship the wrong book due to clerical error, then there's a clear cut violation of expectations with no room for conflicting interpretations.
In the crypto world, NFTs are frequently criticized for this very issue, and it doesn't even leave the digital boundaries: you can prove to have ownership of a token through the blockchain, but whether that token is actually tied to legal ownership of an asset is anyone's guess (case in point, there are various cases of people selling fraudulent NFTs for art they do not own).
Technically language is very interpretable but in some very simple cases it can be mitigated to the point where it's not a realistic issue. Even your book example isn't simple enough to be completely iron clad in all cases. You can receive a book that matches the criteria you provided (say title) but it's not really the book you were thinking of [0].
For more complex things like contracts and laws you have a lot of reasonably vague points that are up for interpretation. Courts reinterpret laws an contracts all the time, it's (part of) their job. Math is nowhere near as interpretable.
> and produced an output as a function of it's actual internal operation (and not a random, accidental bit flip) then it should stand even in front of a judge.
Honest questions to people who are familiar with SmartContracts/Ethereum - how do disputes and adjudicating work in this example then?
Only because human language leaves a lot of room for interpretation. Computer output doesn't, or at the very least not nearly to the same extent. If your smart contract is itself legal (you are legally allowed to formalize those terms), and produced an output as a function of it's actual internal operation (and not a random, accidental bit flip) then it should stand even in front of a judge.