A hazard of being known as a writer is that people often imagine that I know all the rules of grammar and punctuation. I'm pretty good at faking it if all they want is for me to run my eyes over something and tell them if it's right. But when they follow up with "What's the rule?" -- I'm revealed as the empress with no clothes. Here's the latest example. A lawyer-friend (not to be confused with a friendly lawyer) is drafting the deal documents for some billion-dollar transaction. The agreement provides for payment of a sum that's either X or some formula that results in Y. Specifically, the agreement provides that the greater of those two sums must be paid. My friend's question: is the amount to be paid the greater of "X and Y" or the greater of "X or Y"?

My knee-jerk answer was "X and Y," and on further reflection that seems the logical answer, too. There is a universe of two outcomes -- conjunctive, not disjunctive -- and we must choose the greater of those two. But for many people, "the greater of X or Y" sounds right.

What's the answer, and what's the rule?

I don't know the rule, but I know the answer. Rewrite the damn clause so that it requires "the payment of X or Y, whichever is greater."

My knee-jerk answer was "X and Y," and on further reflection that seems the logical answer, too. There is a universe of two outcomes -- conjunctive, not disjunctive -- and we must choose the greater of those two. But for many people, "the greater of X or Y" sounds right.

What's the answer, and what's the rule?

I don't know the rule, but I know the answer. Rewrite the damn clause so that it requires "the payment of X or Y, whichever is greater."