A young boy is looking at a checkers board with one fist leaning against his head as a partially visible adult sits across the table from him , in a room full of people sitting in chairs around tables .
It is probably the case that a boy and his mother play checkers .
It is improbable that a boy and his mother play checkers .
It is probably the case that a boy and his mother play checkers .
A boy and his mother play checkers .