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:
“Ah! I have penetrated to those meadows on the morning of many a first spring day, jumping from hummock to hummock, from willow root to willow root, when the wild river valley and the woods were bathed in so pure and bright a light as would have waked the dead, if they had been slumbering in their graves, as some suppose. There needs no stronger proof of immortality. All things must live in such a light. O Death, where was thy sting? O Grave, where was thy victory, then?”
—Henry David Thoreau (18171862)
“If any doubt has arisen as to me, my country [Virginia] will have my political creed in the form of a Declaration &c. which I was lately directed to draw. This will give decisive proof that my own sentiment concurred with the vote they instructed us to give.”
—Thomas Jefferson (17431826)
“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)