[was@modular was]$ [was@modular was]$ Magma V2.8-2 Wed Jan 16 2002 20:54:02 on modular [Seed = 2448130872] Type ? for help. Type -D to quit. Loading startup file "/home/was/magma/local/emacs.m" Loading "/home/was/magma/local/init.m" > C := HyperellipticCurve([x^3 + x + 1, x^5 - x ]); > P := C![0,-1]; > C19 := ChangeRing(C,GF(19)); >> C19,pi := ChangeRing(C,GF(19)); ^ Runtime error in :=: Expected to assign 2 value(s) but only computed 1 value(s) > C19 := ChangeRing(C,GF(19)); > P19 := C19!P; n> Order(P19); >> Order(P19); ^ Runtime error in 'Order': Bad argument types Argument types given: PtHyp > J := Jacobian(C); > J19 := ChangeRing(J,GF(19)); >> J19 := ChangeRing(J,GF(19)); ^ Runtime error in 'ChangeRing': Bad argument types Argument types given: JacHyp, FldFin > J19 := Jacobian(C19); > P19 := J19!(C19!P); >> P19 := J19!(C19!P); ^ Runtime error in '!': RHS must be either 0 or a sequence of two polynomials LHS: JacHyp RHS: PtHyp > Z := C![0,0]; > P19 := J19![C19!P,C19!Z]; > Order(P19); 123 > >Cbig := ChangeRing(C,GF(NextPrime(10^6))); > > Jbig := Jacobian(Cbig); > Pbig := Jbig![Cbig!P,Cbig!Z]; > Pbig; (x^2, 1000002, 2) > Csim,phi := SimplifiedModel(Cbig); > phi(Pbig); (x^2, x + 1000002, 2) > Psim := phi(Pbig); > Psim; (x^2, x + 1000002, 2) > Order(Psim); 333087389997 > time Order(Psim); 333087389997 Time: 0.010