Timeline for Predicate Logic - Natural Deduction; Assumptions about exists-elimination
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 13, 2018 at 23:15 | comment | added | mcg256 | @ThomasKlimpel Thanks for pointing me there. We were both wrong, but at least someone (@6005) was able to help out! | |
| Aug 8, 2018 at 19:33 | vote | accept | Robert | ||
| Aug 8, 2018 at 9:02 | history | tweeted | twitter.com/StackCompSci/status/1027117740522438657 | ||
| Aug 8, 2018 at 7:30 | comment | added | Thomas Klimpel | @mcg256 Well, it turns out that my suggestion was not the way to go for this proof. Take a look at 6005's answer (and maybe his last comment before I agreed that his solution is correct). This means that your answer is just as incorrect as my suggestion, sorry. | |
| Aug 7, 2018 at 5:35 | answer | added | Caleb Stanford | timeline score: 3 | |
| Aug 7, 2018 at 5:06 | comment | added | Thomas Klimpel | Take a look at cs.uwaterloo.ca/~plragde/cs245old/02-propnd.pdf page 27. In that terminology, you should "introduce a proof box, which is a way of marking the fact that you made the assumption S". Then you can eliminate the implication from you premise, and then eliminate $\exists$. Then you can close the proof box by introducing the implication again, and then ... | |
| Aug 7, 2018 at 0:20 | answer | added | mcg256 | timeline score: 1 | |
| Aug 6, 2018 at 23:43 | comment | added | mcg256 | @ThomasKlimpel S is not a premise, nor is it derivable from the given premise. The premise only states that if S is true, then so is the consequent. | |
| Aug 6, 2018 at 19:44 | comment | added | Thomas Klimpel | You should assume S, then you can ... | |
| Aug 6, 2018 at 18:55 | review | First posts | |||
| Aug 7, 2018 at 1:29 | |||||
| Aug 6, 2018 at 18:50 | history | asked | Robert | CC BY-SA 4.0 |