Magma V2.10-20 Patch Notes

Elliptic Curves¶

• A bug that caused the Mordell-Weil group calculation to hang under rare circumstances has been fixed. Reported by Kaori Suzuki.
• The RootNumber intrinsic is now available.

Geometry¶

• Magma level printing of products of projective schemes has been corrected.
• A error in the checking of input to the function DirectProduct when applied to the ambient spaces of schemes has been fixed.

Groups¶

• An error in the isomorphism returned by the function PCGroup applied to an abelian group has been corrected. Reported by Jon Carlson.
• An error that occurred in the function LowIndexSubgroups in the case in which not all of the composition factors are in the database of maximal subgroups of almost simple groups was fixed. Reported by Markus Grassl.
• An error which caused the Subgroups function to miss some groups when the IsElementaryAbelian flag was set was fixed.

Incidence Structures¶

• A bug in the function IsHadamard that made the function fail to recognise that some matrices over finite fields were not Hadamard has been corrected.

Lie Groups¶

• A bug in the function RootSubdatum which occurred when applied to the standard root datum of type $F_4$. Reported by K Andersen.

Modules¶

• The function Matrix(R, vector) now correctly returns a matrix.

Rings and Fields¶

• An error which caused the different of a relative maximal order of a number field to die unexpectedly has been fixed.
• The / operator when applied to ideals of orders of number fields now returns fractional ideals when each argument is an integral ideal.
• The pSelmerGroup function now works correctly when applied to typed empty sets.
• A bug for SUnitGroups of rank 0 was fixed: formerly Magma would die in this case.
• A bug in IsProbablyPermutationPolynomial when applied to large finite fields has been fixed.

Sets and Sequences¶

• A bug with in for sets and sequences with non-standard universes has been fixed.