Proof
| Proposition | Derivation |
|---|---|
| Given | |
| Given | |
| Given | |
| Material implication | |
| Hypothetical syllogism | |
| Conjunction | |
| Law of Excluded Middle | |
| Constructive dilemma | |
| Tautology |
Read more about this topic: Disjunction Elimination
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)
“Sculpture and painting are very justly called liberal arts; a lively and strong imagination, together with a just observation, being absolutely necessary to excel in either; which, in my opinion, is by no means the case of music, though called a liberal art, and now in Italy placed even above the other twoa proof of the decline of that country.”
—Philip Dormer Stanhope, 4th Earl Chesterfield (16941773)
“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)