The code for the machine to execute is opcodes realized by electric signals. But it's not a good tool to solve problems even when directly translated to assembly. All the other languages were invented for better human affordance and can map to assembly (and opcodes) with logical rules.

The last part is what matters. There's no such clear rules in LLMs behavior. Yes you can get to behave roughly like a rule, but there's no clear cut demarcation between what's in and what's not.