Remove trailing zero terms in a complex
i1 : S=ZZ/101[x,y]/ideal(x*y) o1 = S o1 : QuotientRing |
i2 : C=prependZeroMap appendZeroMap chainComplex(matrix{{x}},matrix{{y}}**S^{ -1},matrix{{x}}**S^{ -2})[1] 1 1 1 1 o2 = 0 <-- S <-- S <-- S <-- S <-- 0 -2 -1 0 1 2 3 o2 : ChainComplex |
i3 : removeZeroTrailingTerms C 1 1 1 1 o3 = S <-- S <-- S <-- S -1 0 1 2 o3 : ChainComplex |
If C has only one nonzero term, then the functions returns two zero maps.
i4 : S=ZZ o4 = ZZ o4 : Ring |
i5 : C=prependZeroMap chainComplex( map(S^0,S^1,0))[3] 1 o5 = 0 <-- 0 <-- ZZ -4 -3 -2 o5 : ChainComplex |
i6 : removeZeroTrailingTerms C 1 o6 = 0 <-- ZZ <-- 0 -3 -2 -1 o6 : ChainComplex |
The object removeZeroTrailingTerms is a method function.