M = V.yAction
A matrix representing the action of y for the hyperelliptic curve E with equation y^2 - (-1)^g * f.
i1 : kk = ZZ/101;
i2 : R = kk[s,t];
i3 : f = (s+2*t)*(s+t)*(s-t)*(s-2*t);
i4 : L0 = randomLineBundle(0,f) o4 = VectorBundleOnE{...1...} o4 : VectorBundleOnE
i5 : M = L0.yAction o5 = {-1} | -29s2+19st+19t2 38s2+9st+47t2 | {-1} | 47s2-22st+t2 29s2-19st-19t2 | 2 2 o5 : Matrix R <-- R
i6 : M^2 - f*id_(source M) o6 = 0 2 2 o6 : Matrix R <-- R
The object yAction is a symbol.