Timeline for Determining if a rational function has a subtraction-free expression
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| May 29, 2018 at 23:06 | vote | accept | Christian Gaetz | ||
| May 29, 2018 at 15:14 | answer | added | David E Speyer | timeline score: 17 | |
| May 24, 2018 at 14:26 | answer | added | Alexandre Eremenko | timeline score: 15 | |
| May 24, 2018 at 14:08 | comment | added | Joel David Hamkins | Do you have an example showing that the positive-values on positive input condition is not also sufficient for subtraction-free representation? If it were a characterization, then we would get decidability, since you search either for a subtraction-free representation or for a negative output, and (if it were a characterization) you'll eventually find one or the other. | |
| May 24, 2018 at 13:57 | comment | added | Christian Gaetz | @JoelDavidHamkins I clarified what I mean, let me know if there are still ambiguities. | |
| May 24, 2018 at 13:55 | history | edited | Christian Gaetz | CC BY-SA 4.0 |
clarified definition
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| May 24, 2018 at 13:46 | comment | added | Joel David Hamkins | Could you clarify when exactly you count two rational expressions as the same? For example, some people would say that $1-x+x^2$ is not the same as $(1+x^3)/(1+x)$, since the former is defined at $x=-1$ and the latter is not; but you want to count these as the same (and that is fine). A similar issue is slightly more complicated in several variables. | |
| May 24, 2018 at 12:13 | history | asked | Christian Gaetz | CC BY-SA 4.0 |