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SpectralSequences :: support(ChainComplex)

support(ChainComplex) -- nonzero parts of a chain complex

Synopsis

Description

Computes the homological degrees in which the chain complex admits a nonzero module

i1 : A = QQ[x,y];
i2 : C = koszul vars A

      1      2      1
o2 = A  <-- A  <-- A
                    
     0      1      2

o2 : ChainComplex
i3 : support C

o3 = {0, 1, 2}

o3 : List
i4 : D = truncate(C,1)

                  2      1
o4 = image 0 <-- A  <-- A
                         
     0           1      2

o4 : ChainComplex
i5 : spots D

o5 = {0, 1, 2}

o5 : List
i6 : support D

o6 = {1, 2}

o6 : List

See also