setupModules -- Creates a list of modules and maps over complete intersection for experiments

Synopsis

• Usage:

  (MM, kk, p) = setupModules(R,M)

• Inputs:
  • R, a list, of complete intersections R_i = S/(f_0..f_(i-1))
  • M, a module, over the ring R_{c-1} where c = length R.
• Outputs:
  • MM, a list, of c+1 modules M_i over R_i
  • kk, a list, of residue class modules k_i of R_i
  • p, a list, of maps, p_i_j: R_j to R_i the projection

Description

i1 : needsPackage "CompleteIntersectionResolutions" -- for "evenExtModule"

o1 = CompleteIntersectionResolutions

o1 : Package

i2 : R =setupRings(3,2);--codims 0..3, degrees = 2

i3 : MM0 = coker random(R_3^2, R_3^{3: -1});

i4 : (M,kkk,p) = setupModules(R,MM0);

i5 : apply(3, j->regularity evenExtModule M_(j+1))

o5 = {1, 2, 3}

o5 : List

See also

• setupRings -- Sets up a complete intersection for experiments