Modus Ponens - Formal Proof

Famous quotes containing the words formal and/or proof:

“That anger can be expressed through words and non-destructive activities; that promises are intended to be kept; that cleanliness and good eating habits are aspects of self-esteem; that compassion is an attribute to be prized—all these lessons are ones children can learn far more readily through the living example of their parents than they ever can through formal instruction.”
—Fred Rogers (20th century)

“In the reproof of chance
Lies the true proof of men.”
—William Shakespeare (1564–1616)