On 18 September 2015 at 19:02, Nils Bruin <nbr...@sfu.ca> wrote: > I wondered about this one: > > sage: k=GF(2) > sage: kx.<x>=GF(2)[] > sage: kxy.<y>=kx[] > sage: kx.extension(y^3+y+1) > Univariate Quotient Polynomial Ring in y over Univariate Polynomial Ring in > x over Finite Field of size 2 (using NTL) with modulus y^3 + y + 1 > sage: exit > Exiting Sage (CPU time 0m0.11s, Wall time 0m21.50s). > Exiting Singular with PID 19781 running > /usr/local/sage/sage-git/local/bin/Singular -t --ticks-per-sec 1000 > --cntrlc=a > > Observations: > > - this extension does not need a name specified, whereas in another case a > name is required: > > sage: kx.<x>=GF(2)[] > sage: k.extension(x^3+x+1) > ValueError: parameter 'conway' is required if no name given
I never used to like Magma's convention of using names like $.1, $.2 for variables when the user did not supply one, but at the moment I am inclined to allow all such constructions to be valid without the user creating a name: deep in some library code a number field was constructed, and needed a name, so used 'a', which was usually OK but not when that name was in use already for a related field. (See http://trac.sagemath.org/ticket/19229 if interested). In that situation no element of the field was ever going to be displayed, so the name is useless. John > > - Polynomial quotient rings seem to trigger starting a separate Singular > process. Shouldn't we be doing this with LibSingular? > > -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-devel@googlegroups.com. > Visit this group at http://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
