--- title: "Magma V2.11-13 Patch Notes" canonical: "https://docs.magma-maths.org/patchnotes/2.11-13.html" source: "https://docs.magma-maths.org/patchnotes/2.11-13.md" --- # Magma V2.11-13 Patch Notes ## Algebras - A bug in the map for `Algebra` of a matrix algebra has been fixed. ## Commutative Algebra - A bug causing a bad slowdown when computing Gröbner bases over $GF(2)$ with field polynomials (non-HFE) has been fixed. ## Groups - A bug with the construction of stabilizer subgroups of matrix groups has been fixed. This caused a crash in V2.11-12 (but not earlier versions) when `BSGS` or `Verify` was used on these subgroups. Bug reported by Markus Grassl. - The order of a matrix group with a single generator is now determined by the order of the generator rather than by `STCS`. Suggested by Derek Holt. - Matrix group `STCS` has been modified to add extra strong generators to force shallow schreier trees (much as the random schreier does). This will hasten membership testing and homomorphism evaluation, and may improve `STCS` performance along the way. - A matrix group bug which sometimes caused `GModule` and `ChiefSeries` to go into an infinite loop has been fixed. ## Number Fields - A problem with the coercion of elements of real quadratic elements into the fixed precision reals has been fixed. The bug was causing Magma internal errors. - A bug in the arithmetic of extensions of non-simple number fields has been fixed. This bug was causing wrong results. ## Polynomial Rings - `IsUnit` and inversion for elements of polynomial quotient rings over prime-power residue rings are now supported properly. ## System and Language - A bug involving print levels in packages has been fixed.