This is from the book by D.J. Velleman-"How to prove it?" Sec 3.5 Excercise 31:
Prove $\exists x(P(x)\rightarrow\forall y P(y))$
Suppose the universe of discourse is set of all men.
Let statement P(x) $:=$ $x$ is married. Then $\forall yP(y)$ means all men are married. Thus, there exists a man, if his marital status is married that means are all men are married. Am I interpreting the statement correctly? It is not abvious to me why this statement is true at all.