But wouldn't this also be an opportunity to dive deeper? Ok, so at a basic level you want both X and Y, but those are mutually exclusive. Why do you want both?

But wouldn't this also be an opportunity to dive deeper? Ok, so at a basic level you want both X and Y, but those are mutually exclusive. Why do you want both? Is one a "must" and the other a "nice to have"? Are X and Y needed in different situations/by different departments? Etc... As a concrete example, a customer demand of "I want the light be on but I also want it to be off" sounds nonsensical, but maybe they really just want to have a light switch.