どっちに解釈したっていいじゃない
An engineer, a physicist, and a mathematician were on a train heading north, and had just crossed the border into Scotland.

* The engineer looked out of the window and said "Look! Scottish sheep are black!"

* The physicist said, "No, no. Some Scottish sheep are black."

* The mathematician looked irritated. "There is at least one field, containing at least one sheep, of which at least one side is black."

variants:

* The statistician : "It's not significant. We only know there's one black sheep"

* The computer scientist : "Oh, no! A special case!"