Timeline for How do most people write permutations?
Current License: CC BY-SA 3.0
9 events
| when toggle format | what | by | license | comment | |
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| Dec 10, 2013 at 8:38 | comment | added | Andrew | @StefanKohl I appreciated your comment, not least because I have had referees say that "most people" use the other convention:) As I grew up using gap perhaps this explains my own preference! | |
| Dec 9, 2013 at 23:19 | comment | added | Johannes Hahn | @StefanKohl I did complain at one time or the other to some GAP developers in person, but of course I know that that is a waste of time. GAP will not change in that regard, because it is now a "somewhat widely used standard" ;-) (which of course has little to do with that being a good notation, but with the use of it for such a long time by so many people) | |
| Dec 9, 2013 at 19:25 | comment | added | darij grinberg | I love the words "somewhat widely used standard". | |
| Dec 9, 2013 at 17:21 | comment | added | Peter Mueller | @Johannes Hahn: Also magma uses this convention. As the actual notation (in gap and magma) for applying the permutation $g$ to the element $a$ is $a\hat{}g$, there is no way to confuse this with a left action. There is a serious source of confusion in sage though: Internally they use a right action, but the notation is $g(a)$. So in general $g(h(a))\ne (g*h)(a)$. | |
| Dec 9, 2013 at 16:53 | comment | added | Stefan Kohl♦ | @JohannesHahn: Really? -- That's interesting ... . To me, multiplying permutations from the left to the right seems and always seemed to be the most natural thing, since one also reads from the left to the right, and not the other way round. I don't remember seeing many complaints on this to GAP Support or on the GAP Forum. | |
| Dec 9, 2013 at 16:02 | comment | added | Johannes Hahn | Even group theorists would like to kick someone's butt sometimes for introducing this stupid convention into GAP. I've literally spend weeks to find unnecessary errors in my GAP code because of this. This is one of the more serious design flaws in the GAP system in my opinion. | |
| Dec 9, 2013 at 13:55 | comment | added | Chris Wuthrich | "widely used standard." No doubt that is true for group theorists, not sure about the rest of us. | |
| S Dec 9, 2013 at 12:56 | history | answered | Stefan Kohl♦ | CC BY-SA 3.0 | |
| S Dec 9, 2013 at 12:56 | history | made wiki | Post Made Community Wiki by Stefan Kohl♦ |