Ext^ZZ(Module,Module) -- compute an Ext module

Ext^ZZ(Module,Module) -- compute an Ext module

Synopsis:

Usage: H = Ext^i(M,N)

Operator: Ext -- compute an Ext module

Input:

i, an instance of class ZZ.

M, an instance of class Module.

N, an instance of class Module.

Output:

H, an instance of class Module: the Ext module of M and N.

If M or N is an ideal or ring, it is regarded as a module in the evident way.