Modus Ponens - Formal Proof

Famous quotes containing the words formal and/or proof:

“On every formal visit a child ought to be of the party, by way of provision for discourse.”
—Jane Austen (1775–1817)

“He who has never failed somewhere, that man can not be great. Failure is the true test of greatness. And if it be said, that continual success is a proof that a man wisely knows his powers,—it is only to be added, that, in that case, he knows them to be small.”
—Herman Melville (1819–1891)