Well, we could imagine someone arguing that differences-between-numbers could be interpreted as a philosophically different entity than the numbers themselves: 3 − 5 = -2, but numbers like -2 which are in ℤ but not ℕ don't have the same kind of easy interpretation as a number you would use to count physical objects with in the way natural numbers like 3 and 5 have.
Well, we could imagine someone arguing that differences-between-numbers could be interpreted as a philosophically different entity than the numbers themselves: 3 − 5 = -2, but numbers like -2 which are in ℤ but not ℕ don't have the same kind of easy interpretation as a number you would use to count physical objects with in the way natural numbers like 3 and 5 have.
in X, such that...
Suggestion: Mark this thread as an "editor only" comment.
Fixed, thanks.