tallySummands -- tally a list of modules up to isomorphism

• Usage:

  tallySummands L

• Inputs:
  • L, a list, of modules or coherent sheaves
• Optional inputs:
  • Homogeneous (missing documentation) => ..., default value true,
  • Strategy (missing documentation) => ..., default value null,
  • Strict (missing documentation) => ..., default value false,
  • Tries (missing documentation) => ..., default value null,
  • Verbose (missing documentation) => ..., default value false,
• Outputs:
  • a tally, whose keys are representatives of isomorphism classes

i1 : R = ZZ/101[x,y]/ideal(x^3, x^2*y^3, y^5);

i2 : F = res(coker vars R, LengthLimit => 5)

      1      2      4      8      16      32
o2 = R  <-- R  <-- R  <-- R  <-- R   <-- R
                                          
     0      1      2      3      4       5

o2 : Complex

i3 : tallySummands summands coker F.dd_5

o3 = Tally{cokernel {7}  | x2   0 0  0 y4 0  | => 3}
                    {8}  | -48y x y3 0 0  0  |
                    {10} | 0    0 0  y x  x2 |
           cokernel {8} | x  0  y4 0   | => 2
                    {8} | -y x2 0  xy3 |
           cokernel {8} | y x | => 3

o3 : Tally