canCurveWithFixedScroll -- Computes a g-nodal canonical curve with a degree k line bundle on a normalized scroll

i1 : (g,k,n) = (8,5,1000);

i2 : Ican = canCurveWithFixedScroll(g,k,n);

               ZZ
o2 : Ideal of ----[t ..t ]
              1009  0   7

i3 : genus Ican, degree Ican, dim Ican

o3 = (8, 14, 2)

o3 : Sequence

i4 : betti res(Ican, DegreeLimit => 1)

            0  1  2  3
o4 = total: 1 15 35 21
         0: 1  .  .  .
         1: . 15 35 21

o4 : BettiTally

i5 : Phi = matrix{{t_0,t_2,t_4,t_6},{t_1,t_3,t_5,t_7}}

o5 = | t_0 t_2 t_4 t_6 |
     | t_1 t_3 t_5 t_7 |

              ZZ          2        ZZ          4
o5 : Matrix (----[t ..t ])  <--- (----[t ..t ])
             1009  0   7          1009  0   7

i6 : Iscroll = minors(2,Phi);

               ZZ
o6 : Ideal of ----[t ..t ]
              1009  0   7

i7 : Ican + Iscroll == Ican

o7 = true