unfold -- converts a differential module into a 1-periodic complex

Synopsis

• Usage:

  unfold(D,a,b)

• Inputs:
  • D, a differential module,
  • a, an integer,
  • b, an integer,
• Outputs:
  • a complex,

Description

i1 : phi = matrix{{0,1},{0,0}};

              2       2
o1 : Matrix ZZ  <-- ZZ

i2 : D = differentialModule(phi);

i3 : unfold(D,-3,4)

       2       2       2       2       2       2       2       2       2
o3 = ZZ  <-- ZZ  <-- ZZ  <-- ZZ  <-- ZZ  <-- ZZ  <-- ZZ  <-- ZZ  <-- ZZ
                                                                      
     -3      -2      -1      0       1       2       3       4       5

o3 : ChainComplex

See also

• differentialModule(Complex) -- converts a complex into a differential module
• resMinFlag -- gives a minimal free flag resolution of a differential module of degree 0
• resDM -- uses a "killing cycles"-style construction to find a free resolution of a differential module
• foldComplex -- converts a chain complex into a differential module