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:
“O, popular applause! what heart of man
Is proof against thy sweet, seducing charms?”
—William Cowper (17311800)
“The source of Pyrrhonism comes from failing to distinguish between a demonstration, a proof and a probability. A demonstration supposes that the contradictory idea is impossible; a proof of fact is where all the reasons lead to belief, without there being any pretext for doubt; a probability is where the reasons for belief are stronger than those for doubting.”
—Andrew Michael Ramsay (16861743)
“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)