Proof
| Proposition | Derivation |
|---|---|
| Given | |
| Given | |
| Material implication | |
| Modus ponens |
| Proposition | Derivation |
|---|---|
| Given | |
| Given | |
| Material implication | |
| Transposition | |
| Modus ponens |
Read more about this topic: Disjunctive Syllogism
Famous quotes containing the word proof:
“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)
“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)
“The thing with Catholicism, the same as all religions, is that it teaches what should be, which seems rather incorrect. This is what should be. Now, if youre taught to live up to a what should be that never existedonly an occult superstition, no proof of this should beMthen you can sit on a jury and indict easily, you can cast the first stone, you can burn Adolf Eichmann, like that!”
—Lenny Bruce (19251966)