Torben Wiedemann

Fix error in membership test for rational functions

2

Fixes the inconsistency in #5993: For a function field `F` over a integral ring `C`, the membership test for `F` should check whether all coefficients lie in the fraction field...

Construction of polynomial ring requires `IsUFDFamily` to be computable

1

Example: ``` ┌───────┐ GAP 4.14.0 of 2024-12-05 │ GAP │ https://www.gap-system.org └───────┘ Architecture: x86_64-pc-linux-gnu-default64-kv9 Configuration: gmp 6.3.0, GASMAN, readline Loading the library and packages ... Packages: AClib 1.3.2, Alnuth 3.2.1,...

Documentation: Clarify meaning of `IsAssocWord`, `IsAssocWordWithOne`, `IsAssocWordWithInverse`

4

Somewhat related to #5991. The [documentation](https://docs.gap-system.org/doc/ref/chap37_mj.html#X7FA8DA728773BA89) claims that > IsAssocWord is the category of associative words in free semigroups, IsAssocWordWithOne is the category of associative words in free monoids (which...

`in` for function fields produces false negatives

2

Consider the following computation: ``` gap> R := FunctionField(Integers, 2); FunctionField(...,[ x_1, x_2 ]) gap> indet := IndeterminatesOfFunctionField(R);; x1 := indet[1];; x2 := indet[2];; gap> left := 2*x1;; right :=...

Missing `hom` method between `WeylGroup` and `GAPGroup`

2

Similar to #4460, but for `WeylGroup`. Setup: ``` julia> G = symmetric_group(3) Sym(3) julia> W = weyl_group(:A, 2) Weyl group for root system defined by Cartan matrix [2 -1; -1...

Difference in handling of non-identical parent groups in `MapFromFunc` and `hom`

5

**Describe the bug** ``` julia> G = symmetric_group(4) Sym(4) julia> f(x) = x f (generic function with 1 method) julia> fmap = MapFromFunc(G, G, f) Map defined by a julia-function...

Improve documentation of `InverseGeneralMapping`

1

The documentation of `InverseGeneralMapping` claims that `Inverse` also works for bijective general mappings; however, this is only true for bijective general mappings where `source = range`. This is correctly explained...