Change log for Magma V2.26-5 (Released 1/6/2021)

Commutative Algebra

·A bug in primary decomposition (arising from PrimeComponents applied to a scheme) has been fixed. Reported by C. Rito.

Hyperelliptic Curves

·A bug in TwoCoverDescentInternal was found and fixed by M Stoll. When the degree of the defining polynomial is odd and the leading coefficient is not a square, the image of the point at infinity on the curve in the Selmer set was computed wrongly.

·A bug in the machinery for constructing the quotient of a curve was found and fixed by M Stoll. The bug could cause errors in the intrinsic SquareFreePart which in turn is used by the intrinsics CurveQuotient and IsHyperelliptic.

p-adic Rings and their Extensions

·The comment attached to SetPrecision has been adjusted to clarify that it changes the DefaultPrecisions rather than the actual precisions of a ring or field and its coefficient rings. Reported by E. Costa.

·An improvement recently made to Factorization of polynomials has been fixed. Reported by M. Stoll.