> The former uses natural numbers, while the latter uses non-negative integers In fact “natural numbers” is ambiguous, as it can both contain zero or exclude i

> The former uses natural numbers, while the latter uses non-negative integers In fact “natural numbers” is ambiguous, as it can both contain zero or exclude it depending on who uses it. See https://en.m.wikipedia.org/wiki/Natural_number https://en.m.wikipedia.org/wiki/Natural_number