Any Magma experts who know what I should write below in place of "Roots(ysoln)"? I basically want the roots of a FldFunRatMElt (variable here happens to show as "$.2"). I would guess there's some simple coercion needed, but I've had no luck finding examples for this on the internet. I really just need to know the rational roots. Thanks!

```
PP<x,y,z>:=ProjectiveSpace(Rationals(),2);
CU:=Curve(PP, (z + x - y)*(z - x + y)*(-z + x + y)*(z + x + y));
curve:=DefiningPolynomials(CU)[1];
ysoln:=Evaluate(curve,[1,y,1]);
ysoln; Type(ysoln);
ysoln:=Evaluate(ysoln,[1,y,1])/y;
ysoln:=Evaluate(ysoln,[1,y,1])*y;
// Other things really happen above, but denominator becomes 1
ysoln; Type(ysoln);
// I would like to just do this
Roots(ysoln);
// but Magma refuses...
// I know the Roots function works if set-up properly:
R<y>:=PolynomialRing(Rationals());
fy:=y^3-8;
Roots(fy);
```