Hyperelliptic Curves [HB 92]

Removals and Changes:

• The input arguments of the HyperellipticCurve intrinsic that creates an hyperelliptic curve have been swapped for general consistency. If f (x) and h(x) are two univariate polynomials then HyperellipticCurve(f, h) returns the curve defined by the equation y² + h(x)y = f (x). (Formerly the syntax was HyperellipticCurve(h, f).)
• Again for consistency, the input polynomials have been swapped in the intrinsics IgusaInvariants, JInvariants, ScaledIgusaInvariants and IgusaClebschInvariants. A typical call to compute the Igusa J-invariants of the curve y² + h(x)y = f (x) would be IgusaInvariants(f, h).