Re: [sage-support] Re: confused about primality of Ideal(1)
upstream report link: http://www.singular.uni-kl.de:8002/trac/ticket/550 Remark: minimal_associated_primes() and almost all routines based on decomposition routines from Singular's 'primdec.lib' are affected, too. Try R. = QQ[] I = Ideal( R(1) ) I.minimal_associated_primes() Am Montag, 27. Januar 2014 15:45:24 UTC+1 schrieb John Cremona: > > See http://trac.sagemath.org/ticket/15745 > > John > > On 27 January 2014 14:39, John Cremona > > wrote: > > On 27 January 2014 14:37, > > wrote: > >> Ok, I will do the upstream-report (Singular trac at > >> http://www.singular.uni-kl.de:8002/trac/newticket) > >> > >>> John Cremona: [...] which I'm sure has been reported before. > >> > >> > >> I could not find a corresponding ticket in sage trac and cannot > >> currently login. Could someone open a that ticket in sage-trac if > necessary? > > > > I will do that (unless Peter has already). Despite Singular, Sage > > can check for the unit ideal in this and related functions. > > > > John > > > >> > >> > >> Jack > >> > >> Am Montag, 27. Januar 2014 15:15:08 UTC+1 schrieb Peter Bruin: > >>> > >>> Hello, > >>> > >>> > I'm a bit confused about Sage's answer if Ideal(1) is prime. > >>> > > >>> > R.= QQ[] > >>> > I = Ideal(R(1)) > >>> > I.is_prime() > >>> > > >>> > Sage (5.11, not only) says yes, > >>> > conflicting to the definition, > >>> > http://en.wikipedia.org/wiki/Prime_ideal > >>> > Has somebody an expanation of this behaviour? > >>> > >>> The example Singular session below suggests that the problem lies in > >>> Singular (I'm not too familiar with Singular, but I think the answers > >>> should all be the same, and only primdecSY(J) seems to be correct). > >>> > >>> Peter > >>> > >>> > >>> $ sage -singular > >>> SINGULAR / > >>> Development > >>> A Computer Algebra System for Polynomial Computations / > version > >>> 3-1-5 > >>>0< > >>> by: W. Decker, G.-M. Greuel, G. Pfister, H. Schoenemann \ Jul > 2012 > >>> FB Mathematik der Universitaet, D-67653 Kaiserslautern\ > >>> > LIB "primdec.lib" > >>> (...) > >>> > ring R = 0, (x, y), dp; > >>> > ideal I = 1; > >>> > primdecSY(I); > >>> [1]: > >>>[1]: > >>> _[1]=1 > >>>[2]: > >>> _[1]=1 > >>> > primdecGTZ(I); > >>> [1]: > >>>[1]: > >>> _[1]=1 > >>>[2]: > >>> _[1]=1 > >>> > ideal J = x, x + 1; > >>> > primdecSY(J); > >>> empty list > >>> > primdecGTZ(J); > >>> [1]: > >>>[1]: > >>> _[1]=1 > >>>[2]: > >>> _[1]=1 > >>> > >> -- > >> 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...@googlegroups.com . > >> To post to this group, send email to > >> sage-s...@googlegroups.com. > > >> Visit this group at http://groups.google.com/group/sage-support. > >> For more options, visit https://groups.google.com/groups/opt_out. > -- 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 post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/d/optout.
Re: [sage-support] Re: confused about primality of Ideal(1)
See http://trac.sagemath.org/ticket/15745 John On 27 January 2014 14:39, John Cremona wrote: > On 27 January 2014 14:37, wrote: >> Ok, I will do the upstream-report (Singular trac at >> http://www.singular.uni-kl.de:8002/trac/newticket) >> >>> John Cremona: [...] which I'm sure has been reported before. >> >> >> I could not find a corresponding ticket in sage trac and cannot >> currently login. Could someone open a that ticket in sage-trac if necessary? > > I will do that (unless Peter has already). Despite Singular, Sage > can check for the unit ideal in this and related functions. > > John > >> >> >> Jack >> >> Am Montag, 27. Januar 2014 15:15:08 UTC+1 schrieb Peter Bruin: >>> >>> Hello, >>> >>> > I'm a bit confused about Sage's answer if Ideal(1) is prime. >>> > >>> > R.= QQ[] >>> > I = Ideal(R(1)) >>> > I.is_prime() >>> > >>> > Sage (5.11, not only) says yes, >>> > conflicting to the definition, >>> > http://en.wikipedia.org/wiki/Prime_ideal >>> > Has somebody an expanation of this behaviour? >>> >>> The example Singular session below suggests that the problem lies in >>> Singular (I'm not too familiar with Singular, but I think the answers >>> should all be the same, and only primdecSY(J) seems to be correct). >>> >>> Peter >>> >>> >>> $ sage -singular >>> SINGULAR / >>> Development >>> A Computer Algebra System for Polynomial Computations / version >>> 3-1-5 >>>0< >>> by: W. Decker, G.-M. Greuel, G. Pfister, H. Schoenemann \ Jul 2012 >>> FB Mathematik der Universitaet, D-67653 Kaiserslautern\ >>> > LIB "primdec.lib" >>> (...) >>> > ring R = 0, (x, y), dp; >>> > ideal I = 1; >>> > primdecSY(I); >>> [1]: >>>[1]: >>> _[1]=1 >>>[2]: >>> _[1]=1 >>> > primdecGTZ(I); >>> [1]: >>>[1]: >>> _[1]=1 >>>[2]: >>> _[1]=1 >>> > ideal J = x, x + 1; >>> > primdecSY(J); >>> empty list >>> > primdecGTZ(J); >>> [1]: >>>[1]: >>> _[1]=1 >>>[2]: >>> _[1]=1 >>> >> -- >> 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 post to this group, send email to sage-support@googlegroups.com. >> Visit this group at http://groups.google.com/group/sage-support. >> For more options, visit https://groups.google.com/groups/opt_out. -- 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 post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/groups/opt_out.
Re: [sage-support] Re: confused about primality of Ideal(1)
On 27 January 2014 14:37, wrote: > Ok, I will do the upstream-report (Singular trac at > http://www.singular.uni-kl.de:8002/trac/newticket) > >> John Cremona: [...] which I'm sure has been reported before. > > > I could not find a corresponding ticket in sage trac and cannot > currently login. Could someone open a that ticket in sage-trac if necessary? I will do that (unless Peter has already). Despite Singular, Sage can check for the unit ideal in this and related functions. John > > > Jack > > Am Montag, 27. Januar 2014 15:15:08 UTC+1 schrieb Peter Bruin: >> >> Hello, >> >> > I'm a bit confused about Sage's answer if Ideal(1) is prime. >> > >> > R.= QQ[] >> > I = Ideal(R(1)) >> > I.is_prime() >> > >> > Sage (5.11, not only) says yes, >> > conflicting to the definition, >> > http://en.wikipedia.org/wiki/Prime_ideal >> > Has somebody an expanation of this behaviour? >> >> The example Singular session below suggests that the problem lies in >> Singular (I'm not too familiar with Singular, but I think the answers >> should all be the same, and only primdecSY(J) seems to be correct). >> >> Peter >> >> >> $ sage -singular >> SINGULAR / >> Development >> A Computer Algebra System for Polynomial Computations / version >> 3-1-5 >>0< >> by: W. Decker, G.-M. Greuel, G. Pfister, H. Schoenemann \ Jul 2012 >> FB Mathematik der Universitaet, D-67653 Kaiserslautern\ >> > LIB "primdec.lib" >> (...) >> > ring R = 0, (x, y), dp; >> > ideal I = 1; >> > primdecSY(I); >> [1]: >>[1]: >> _[1]=1 >>[2]: >> _[1]=1 >> > primdecGTZ(I); >> [1]: >>[1]: >> _[1]=1 >>[2]: >> _[1]=1 >> > ideal J = x, x + 1; >> > primdecSY(J); >> empty list >> > primdecGTZ(J); >> [1]: >>[1]: >> _[1]=1 >>[2]: >> _[1]=1 >> > -- > 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 post to this group, send email to sage-support@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-support. > For more options, visit https://groups.google.com/groups/opt_out. -- 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 post to this group, send email to sage-support@googlegroups.com. Visit this group at http://groups.google.com/group/sage-support. For more options, visit https://groups.google.com/groups/opt_out.
