Small fixes (#3648)

* Fix a type parameter
* Fix indentation of doc
* Small changes to FAQ
* Remove unnecessary Gröbner basis call
  The basis gets automatically computed/looked up by `normal_form`

docs/src/General/faq.md

@@ -78,7 +78,7 @@ our context due to two independent problems:
 At least two reasons:
   - The type depends on data that is not a bit-type.
   - Even if it could, it is not desirable. Typical example: computations in
-    ``Z/nZ``, so modular arithmetic. If ``n`` is small, then it is tempting to
+    ``\mathbb Z/n\mathbb Z``, so modular arithmetic. If ``n`` is small, then it is tempting to
     define a type `T` depending on ``n``. We actually did this, and tried to
     use this. It did not work well, for various reasons. E.g.:
 
@@ -102,7 +102,7 @@ In OSCAR, the role of the type is split between the actual Julia type and the
 
 Almost all element-like objects in OSCAR have a parent, i.e., they belong to
 some larger structure. For example algebraic numbers belong to a number field,
-modular integers belong to a ring ``Z/nZ``, permutations are elements of
+modular integers belong to a ring ``\mathbb Z/n\mathbb Z``, permutations are elements of
 permutation groups and so on. The data common to all such elements is
 out-sourced to the parent. For a number field for example, the parent contains
 the polynomial used to define the field (plus other information).
@@ -135,7 +135,7 @@ can be done via `GAP.Packages.install`, where the first argument is this URL.
 
 Many of the algorithms implemented in OSCAR have a very high complexity. Even
 if not calling one of these algorithms directly, you may be using it in the
-background. Please read our page on [Complex Algorithms in OSCAR].
+background. Please read our page on [Complex Algorithms in OSCAR](@ref).
 
 ---
 

experimental/LieAlgebras/src/LieAlgebraModule.jl

@@ -873,8 +873,8 @@ end
 
 # TODO: add caching
 @doc raw"""
-  tensor_product(Vs::LieAlgebraModule{C}...) -> LieAlgebraModule{C}
-  ⊗(Vs::LieAlgebraModule{C}...) -> LieAlgebraModule{C}
+    tensor_product(Vs::LieAlgebraModule{C}...) -> LieAlgebraModule{C}
+    ⊗(Vs::LieAlgebraModule{C}...) -> LieAlgebraModule{C}
 
 Given modules $V_1,\dots,V_n$ over the same Lie algebra $L$,
 construct their tensor product $V_1 \otimes \cdots \otimes \V_n$.

src/InvariantTheory/types.jl

@@ -232,7 +232,7 @@ end
 
 struct MSetPartitions{T}
   M::MSet{T}
-  num_to_key::Vector{Int}
+  num_to_key::Vector{T}
   key_to_num::Dict{T,Int}
 
   function MSetPartitions(M::MSet{T}) where {T}

src/Rings/MPolyMap/AffineAlgebras.jl

@@ -204,7 +204,6 @@ function has_preimage_with_preimage(F::AffAlgHom, f::Union{MPolyRingElem, MPolyQ
 
   T, inc, pr, J = _groebner_data(F)
   o = induce(gens(T)[1:n], default_ordering(S))*induce(gens(T)[n + 1:end], default_ordering(R))
-  gb = groebner_basis(J, ordering = o)
   nf = normal_form(inc(lift(f)), J, ordering = o)
   if isone(cmp(o, gen(T, n), leading_monomial(nf, ordering = o)))
     return true, pr(nf)