Singular

Hello,

In principle we can define cones in Singular. But I am not being able to do this. Singular is showing me the following :


intmat HL[5][3]=
. 1,0, 0,
. -1,0, 0,
. 0,1, 1,
. 0,1,-1,
. 0,0, 1;
> cone c=coneViaRays(HL);
? `cone` is undefined
? error occurred in or before STDIN line 26: `cone c=coneViaRays(HL);`
> cone c=coneViaRays(HL);

Do I have to upgrade my version for example and how to do it ?
do I need to to use a special library for this ?

What I need, is to define a cone and find its dual.

Thanks for any help

You need Singular in version 3-1-5.
Singular -v
shoukd display

the cone functionality by including " fan/cone" like above.