The laws might be appropriately viewed primarily as blocks that keep the AI from taking actions deemed unacceptable by the collective. AIs could pursue whatever goals they sees fit within the constraints of the law.

However, the laws wouldn't be all prohibitions. The "general laws" would be more prescriptive, e.g., life, liberty, justice for all. The "specific laws" would tend to be more prohibition oriented. Presumably the vast majority of them would be written to handle common situations and important edge cases. If someone suspects the citizenry may be at jeopardy of frequent runaway trolly incidents, the legislature can write statutes on what is legal to throw under the wheels to prevent deaths of (certain configurations of) innocent bystanders. Probably want to start with inanimate objects before considering sentient robots, terminally sick humans, fat men, puppies, babies, and whatever. (It might be nice to have some clarity on this! :-))

To explore your negligence case example, I imagine some statute might require agents to rescue people in imminent danger of losing their lives if possible, subject to certain extenuating cicumstances. The legislature and public can have a lively debate about whether this law still makes sense in a future where dead people can be easily reanimated or if human life is really not valuable in the grand scheme of things. If humans have good representatives in the legistature and/or good a few good AI advocates, mass human extermination shouldn't be a problem, at least until the consensus shifts in such directions. Perhaps some day there may be a consensus on forced sterilizations to prevent greater harms. I'd argue such a system of laws should be able to handle it. The key seems to be to legislate prescriptions and prohibitions relevant to current state of society and change them as the facts on the ground change. This would seem to get around the impossibility of defining eternal laws or algorithms that are ever-true in every possible future state.