Before fitting the traditional statement forms into these general statement forms we need to look at the notion of a tautology. A tautology is a statement that is necessarily true because it is constructed in such a way that it cannot be false. For example, "A tree is a tree" is a tautology, and so are "All oak trees are trees," "All oak trees are oak," etc. Moreover, since tautologies are always true they always "go without saying" since they never convey information of anything that might have been otherwise.
Now in the forms above x can be instantiated with, i.e., can be replaced by, any nonnegative number (although for simplicity's sake we will stay with whole numbers). However, there are two interesting cases where the use of zero produces tautologies. They are the two particular forms, viz., "At least ∅+0 A are B" and "At most ∀-0 A are B."
That is, regardless of what is substituted for terms A and B in these forms, the resulting sentences cannot be false. The first has to be true since, if "At least ∅+0 A are B" were false, it would mean that fewer than zero members of category A are B; but this is impossible since zero is the fewest number of members any category can possibly have. And for the second, if "At most ∀-0 A are B" were false, it would mean that more than all (i.e., more than all minus 0) members of category A are B; but this is impossible since all is the greatest number of members that any category can possibly have.