Proof
| Proposition | Derivation |
|---|---|
| Given | |
| Given | |
| Transposition | |
| Law of the Excluded Middle | |
| Conjunction | |
| Constructive dilemma | |
| Material implication |
Read more about this topic: Hypothetical Syllogism
Famous quotes containing the word proof:
“It comes to pass oft that a terrible oath, with a swaggering accent sharply twanged off, gives manhood more approbation than ever proof itself would have earned him.”
—William Shakespeare (15641616)
“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 (18191891)
“A short letter to a distant friend is, in my opinion, an insult like that of a slight bow or cursory salutationa proof of unwillingness to do much, even where there is a necessity of doing something.”
—Samuel Johnson (17091784)