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CHANGES.md

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+# CHANGES to the 'ModIsom' GAP package
+
+## 3.2.0 (unreleased)
+
+ - prefixed the global variables defined in `read.g` with `MIP_`, e.g.
+   `COVER_LIMIT` is now `MIP_COVER_LIMIT`
+ - `IsCoveredByTheory` and `IsCoveredByTheoryAllFields` now do what their
+   names suggest
+
+## 3.1.0 (2026-01-09)
+
+ - fixed `JenningsInfoAllFields`, which used an invariant valid only over
+   `GF(p)`, namely the quotient by the second dimension subgroup
+   (Passi-Sehgal 72); this made the results of versions 3.0.0 and 3.0.1
+   mathematically wrong
+ - `JenningsBoundPairwise` now does what it always claimed to do; the old
+   function is now called `JenningsBoundPairwiseWithIds`
+ - fixed a bug in `MIPBinsByGTInternal` and `MIPBinsByGTAllFieldsInternal`
+   which could cause break loops, as invariants were applied to empty bins
+ - added the invariant `G/Agemo(G')` for `G'` cyclic and `G` 2-generated
+   (Margolis-Sakurai 25) to `CyclicDerivedInfo` and
+   `CyclicDerivedInfoAllFields`
+ - `IsCoveredByTheoryAllFields` now covers metacyclic groups
+   (Margolis-Sakurai 25, Theorem 3.6)
+ - `IsCoveredByTheory` now covers Roehl 90, Theorem 3.1.2, using
+   Minac-Rogelstad-Tan 2016, Proposition 3.4 for the dimensions of
+   dimension subgroup quotients of free pro-p groups
+ - `IsCoveredByTheory` and `SandlingInfo` now cover Brenner-Garcia-Lucas 24,
+   Theorems A and B
+ - `MIPSplitGroupsByAlgebras` now returns 1 instead of 0 when the first
+   layers of the group algebras are not isomorphic, for consistency with
+   its other return values
+ - changed the output of `NormalSubgroupsInfo` so that one can tell which
+   entry belongs to which subgroup; the invariant itself is unchanged
+ - fixed several invariant functions which raised errors for groups they
+   were not written for, such as abelian groups
+ - extended the test files
+ - minor manual changes
+
+## 3.0.1 (2024-12-28)
+
+ - made LAGUNA a required package, which avoids warnings when ModIsom is
+   loaded
+
+## 3.0.0 (2024-09-23)
+
+This release merges the functionality of ModIsomExt, a package by Leo
+Margolis and Tobias Moede, into ModIsom; see
+<https://doi.org/10.1016/j.jaca.2022.100001>. ModIsomExt installed its
+functions as methods; here they are all `BindGlobal`.
+
+New group-theoretic invariants and splitting functions (`detbins.gi`):
+
+ - `RefineBins`, which refines lists of groups and not only of ids,
+   `ConjugacyClassInfo` (with the parameter of Parmenter-Polcino
+   Milies), `JenningsInfo` (with Hertweck's `G/D4(G)` and better id
+   recognition), `SandlingInfo` (with Baginski and Margolis-Moede on
+   small group rings), `BaginskiInfo` (Baginski 99), `CenterDerivedInfo`,
+   `FrattiniInfo`, `JenningsDerivedInfo`, `BaginskiCarantiInfo`,
+   `NilpotencyClassInfo` and `DimensionTwoCohomology`, all from ModIsomExt
+ - `JenningsInfoAllFields`, using only subsequent Jennings quotients
+ - `DimensionSecondHochschild`, the dimension of the second Hochschild
+   cohomology group
+ - `IsCoveredByTheory` extended by various new results, and the new
+   `IsCoveredByTheoryAllFields`
+ - `Theorem41MS22` for the result of Margolis-Stanojkovski
+ - `MaximalAbelianDirectFactor` and `MaximalElementaryAbelianDirectFactor`
+   for cancelling factors
+ - `AgemoInvariantAllM`, `OmegaInvariantAllM`, `AgemoCenterInvariantAllM`
+   and `NormalSubgroupsInfo`, based on Garcia-Lucas and
+   Margolis-Sakurai-Stanojkovski
+ - `CyclicDerivedInfo` and `CyclicDerivedInfoAllFields`, based on
+   Garcia-Lucas-Del Rio-Stanojkovski and Garcia-Lucas-Del Rio
+ - `MIPBinsByGTInternal` extended by the new invariants and an option to
+   turn off cohomology computations; `BinsByGT` now takes 2-4 arguments
+   and uses the new invariants
+ - `MIPBinsByGTAllFieldsInternal` and `BinsByGTAllFields` for all fields
+ - `MIPSplitGroupsByGroupTheoreticalInvariants` and its
+   `NoCohomology`, `AllFields` and `AllFieldsNoCohomology` variants, which
+   take just a list of groups
+
+Algebra side (`chkbins.gi`, formerly `checkbin.gi`):
+
+ - `MIPBinSplit` from ModIsomExt, with a fix of the main function and a
+   change allowing the field to be increased
+ - `MIPSplitGroupsByAlgebras`, which takes a list of groups and optionally
+   a number by which to increase the field
+ - reports on time and similar data, as in ModIsomExt
+
+New files:
+
+ - `collect.gi` from ModIsomExt: computing with Jennings bases in Loewy
+   series quotients of the augmentation ideal, plus the new function
+   `ModIsomTable`
+ - `jenningsBounds.gi` and `jenningsConjecture.gi`: the Jennings bound
+   functions, which in ModIsomExt lived in `detbins.gi`
+ - `kernelsize.gi`: kernel sizes of power maps
+ - `tabletoalgebraandback.gi`: `MIPElementTableToAlgebra` and
+   `MIPElementAlgebraToTable`, converting elements between the group
+   algebra and the table
+ - `detbinsRT.gi`: the ring-theoretic functions, from the second half of
+   the old `checkbin.gi`, now `chkbins.gi`
+
+Other changes:
+
+ - fixed `PowerBasisWeights` in `fprint.gi`, as already done in ModIsomExt
+ - documented the new functions, the changes to existing ones, and a number
+   of functions that were undocumented before
+
+## 2.5.4 (2023-02-27)
+
+## 2.5.3 (2022-08-09)
+
+## 2.5.2 (2022-04-29)
+
+## 2.5.1 (2020-01-28)
+
+## 2.5.0 (2019-02-19)
+
+## 2.4.0 (2018-09-16)