Thanks! I can try to investigate, but in the meantime I will open a ticket for this on trac.
On Sunday, June 20, 2021 at 7:32:47 AM UTC-4 Kwankyu wrote: > Hi, > > On Sunday, June 20, 2021 at 10:18:50 AM UTC+9 zsc...@gmail.com wrote: > >> I have reason to believe that the point P is not torsion and so Magma is >> correct and Sage is incorrect. I don't know enough about the algorithms >> used to work with points on hyperelliptic Jacobians and so I'm not >> confident in my ability to track down what's going on. >> > > By my own computation, I confirm that Sage is incorrect. Looking at the > Sage source code, I see that Sage uses Cantor's reduction algorithm based > on Mumford representation of divisors by ideals. Sage wrongly computes 5*P > to (1) unit ideal. So I guess there seems a bug in the implementation of > Cantor's algorithm... > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-support+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/sage-support/a6be3412-36b0-4470-ad82-bdcadb74fbd2n%40googlegroups.com.
