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:
“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)
“From whichever angle one looks at it, the application of racial theories remains a striking proof of the lowered demands of public opinion upon the purity of critical judgment.”
—Johan Huizinga (18721945)
“There are some persons in this world, who, unable to give better proof of being wise, take a strange delight in showing what they think they have sagaciously read in mankind by uncharitable suspicions of them.”
—Herman Melville (18191891)