This is a MAGMA-readable 3-tuple. The first entry is a polynomial
f(x) of degree n which defines the degree n field
K_{f} generated by the eigenvalues
a_{p}. The second entry is a sequence of sequences of
length n each of which defines a_{p} on a basis
for K_{f}. The third entry defines an embedding of
that basis for K_{f} into the field
Q[x]/(f(x)).