- 20,819
- 28,467
But this argument is essentially practicability as it is to exclude units to be prime. I have no problem when people work with ##\mathbb{N}_0## though.micromass said:But sure, ##0## is unnatural. I have 2 apples and give 2 apples to my brother. What I have left is nothing natural??
Also, axiomatic set theory is pretty clear on the issue that ##0## should be a natural number. You'd make a mess out of the theory otherwise.
