v=[1,1.,Mod(1,6),1/2,I+Mod(1,3), O(2), quadgen(5)*Mod(1,3), Mod(1,x)];
for (i=1,#v, print(characteristic(v[i])))
characteristic(v)
characteristic(matid(2)*Mod(1,2))
characteristic([])
characteristic(List())
characteristic(ffgen(2^3))
characteristic([ffgen(2),ffgen(3)])
characteristic([ffgen(2),Mod(1,3)])
