I can see multiple applications of this to replace CFDs, options, swaps, even sports wagering applications. It would provide a public audit trail that can't be

I can see multiple applications of this to replace CFDs, options, swaps, even sports wagering applications. It would provide a public audit trail that can't be disputed and might actually be _more_ useful for regulators to understand insider trading, etc. whilst also almost eliminating transaction costs. What concerns me is the evaluation of the "do" - what is responsible for determining if something is "done"? How does contract dispute work within Ethereum? I can see Gnosis is doing predictive markets work, and I get that in theory it's possible, but are there mechanisms in order to evaluate whether a contract term has been met autonomously with Codex or other tools in the Ethereum world? If so, what are they?