This function checks if the module
M is a quotient of its
ambient free module by examining its matrix of
generators.
i1 : R = ZZ/101[a,b,c];
|
i2 : M = R^1/(a^2,b^2,c^2)
o2 = cokernel | a2 b2 c2 |
1
o2 : R-module, quotient of R
|
i3 : isQuotientModule M
o3 = true
|
The image of a map from a free module to the first generator of
M yields an equivalent module which is
not presented as a quotient.
i4 : f = M_{0}
o4 = | 1 |
o4 : Matrix
|
i5 : N = image f
o5 = subquotient (| 1 |, | a2 b2 c2 |)
1
o5 : R-module, subquotient of R
|
i6 : M == N
o6 = true
|
i7 : isQuotientModule N
o7 = false
|