bugreport

[Martin Albrecht]

Hi there,

I am updating our Singular version to 3-1-1-0 and noticed that in genus() in
normal.lib you now have:

if(char(basering)>0)
{
def R1=changeord("dp");
setring R1;
ideal J=std(imap(R0,I));
if(dim(J)!=1){ERROR("ideal defines not a curve");}
def S=changevar(varstr(R)+",@t");
setring S;
ideal J=imap(R1,J);
J=std(homog(J,@t));
int pa=1-hilbPoly(J)[1];
setring R0;
list nor=normalP(I);
return(pa-nor[2][2]);
}

This gives me an error because "R" is not defined.

Cheers,
Martin

--
name: Martin Albrecht
_pgp: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0x8EF0DC99
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_www: http://www.informatik.uni-bremen.de/~malb
_jab: martinr...@jabber.ccc.de

[Hans Schoenemann]

On Fri, Mar 05, 2010 at 01:22:33PM +0000, Martin Albrecht wrote:
Hi,
this is a typo, sorry for that.
It should be R1 at that place:

> if(char(basering)>0)
> {
> def R1=changeord("dp");
> setring R1;
> ideal J=std(imap(R0,I));
> if(dim(J)!=1){ERROR("ideal defines not a curve");}

> def S=changevar(varstr(R1)+",@t");
====

> setring S;
> ideal J=imap(R1,J);
> J=std(homog(J,@t));
> int pa=1-hilbPoly(J)[1];
> setring R0;
> list nor=normalP(I);
> return(pa-nor[2][2]);
> }
>

Hans

[Hans Schoenemann]

On Fri, Mar 05, 2010 at 01:22:33PM +0000, Martin Albrecht wrote:

> Hi there,
>
> I am updating our Singular version to 3-1-1-0 and noticed that in genus() in
> normal.lib you now have:
>

.....
The problems with genus in characteristic p should be fixed in
Singular-3-1-1-3

Hans Schoenemann

[Martin Albrecht]

Great, I'll try to provide an updated SPKG before Sage Days 23.5 starts so
that we all have a good basis to work from.