(cohomology,ZZ,Module)

HH^i(M) -- computes the i-th local cohomology of M with respect to the maximal ideal generated by the variables of the ring.

i1 : R = QQ[x,y];

i2 : HH^2 (R^{-3})



o2 = cokernel {0} | 0 -y x |

              {0} | y x  0 |



                              2

o2 : R - module, quotient of R

i3 : HH^2 (R^{-4})



o3 = cokernel {0} | 0 0  -y x |

              {0} | 0 -y x  0 |

              {0} | y x  0  0 |



                              3

o3 : R - module, quotient of R