Patch Notes

Magma V2.18-12 Patch Notes

Patch release for Magma V2.18-12. Updated areas: Algebraic Curves, Algebraic Fields, Algebraic Number Fields, Elliptic curves, Groups and 3 more.

8 areas

Algebraic Curves

  • Some problems with residue fields of curves have been fixed.
  • An incorrect assertion that was causing occasional crashs in IsHyperelliptic and CurveQuotient has been fixed.

Algebraic Fields

  • Residue fields of some places have been optimized.
  • The inertia degree computation of some prime ideals of relative extensions has been corrected.

Algebraic Number Fields

  • A memory issue in ext<> has been fixed.
  • An error message from meet of an order with a number field has been corrected.

Elliptic curves

  • TwoDescent of elliptic curves over Q has been improved, fixing extremely bad performance for curves of large conductor with a single two-torsion point. Reported by R. Rathbun.
  • In EightDescent, some bugs have been fixed which triggered runtime errors in occasional cases. Reported by R. Rathbun.
  • A bug has been fixed in EllipticCurveSearch which caused it to sometimes be very slow for fields of degree 4 or more. Reported by L. Dembele.

Groups

  • The construction of BSGS for a matrix group will check if the group is known to be infinite, and will trigger a runtime error if it is. Reported by M. Grassl.
  • A crash in ClassicalMaximals when the normalise parameter is set to true has been fixed. Reported by E. O'Brien, fixed by D. Holt.

Lattices

  • A crash computing isometry of two lattices with empty sequences of extra forms has been fixed. Reported by M. Kirschmer.

Modular forms

Polynomial Rings

  • A crash in ColonIdeal for ideals over residue class rings has been fixed. Reported by J. Shotton.
  • XGCD now returns all 3 return values when called directly in print mode. Reported by D. Passman.
  • Evaluation of polynomials at matrices over finite fields has been sped up.