ChainComplexMap ^ ZZ -- iterated composition

Synopsis

• Operator: ^

• Usage:

  f^n

• Inputs:
  • f, a chain complex map, or a a graded module map
  • n, an integer
• Outputs:
  • a chain complex map, the composite f o f o ... o f (n times)

Description

One use of this function is to determine if a chain complex is well-defined. The chain complex will be well-defined if the square of the differential is zero.

i1 : R = QQ[x,y,z];

i2 : C = res coker vars R

      1      3      3      1
o2 = R  <-- R  <-- R  <-- R  <-- 0
                                  
     0      1      2      3      4

o2 : ChainComplex

i3 : C.dd^2 == 0

o3 = true

See also

• ChainComplex -- the class of all chain complexes