Macaulay 2, version 0.9.20 with packages: Classic, Elimination, LLLBases, Parsing, PrimaryDecomposition, SchurRings, TangentCone i1 : R=QQ[x,y,z] o1 = R o1 : PolynomialRing i2 : I=ideal(x^2,x*y,z^5) 2 5 o2 = ideal (x , x*y, z ) o2 : Ideal of R i3 : M=R^1/I o3 = cokernel | x2 xy z5 | 1 o3 : R-module, quotient of R i4 : C=res M 1 3 3 1 o4 = R <-- R <-- R <-- R <-- 0 0 1 2 3 4 o4 : ChainComplex i5 : C.dd 1 3 o5 = 0 : R <---------------- R : 1 | x2 xy z5 | 3 3 1 : R <---------------------- R : 2 {2} | -y -z5 0 | {2} | x 0 -z5 | {5} | 0 x2 xy | 3 1 2 : R <-------------- R : 3 {3} | z5 | {7} | -y | {7} | x | 1 3 : R <----- 0 : 4 0 --From this we can see that, for example, Tor_2(M,R/) = Q^3.