[leafmeal]

immutable had a different meaning in common parlance than it does in datatypes. And even in datatypes usually you end up creating a new "copy" of the thing but with more info appended. The original remains as it was, unchanged (until garbage collection of course)

[Cupertino95014]

I don't see what this contributes. Written laws are immutable in the common sense of the word. That's what "legal certainty" means as an ideal: citizens can know what they'll be punished for. If it's unclear talk to your lawyer.