All X Are Yish

"All elements of set X have property Y."

"But a is an element of X and doesn't have property Y."

"Yes, a is an exception."

"And b is an element of X and doesn't have property Y."

"Yes, yes, b is also an exception."

"And c ..."

Etc. many times.

But then finally:

"Ah hah! Epsilon! Epsilon is an element of X and most definitely and obviously and unpleasantly has property Y!"

"So you're saying that epsilon is an excep--"

Triumphantly: "Epsilon proves what I've been saying all along! All elements of set X have property Y!"