diff --git a/src/WreathProducts.jl b/src/WreathProducts.jl index e4f3490..5232446 100644 --- a/src/WreathProducts.jl +++ b/src/WreathProducts.jl @@ -7,17 +7,17 @@ export WreathProduct, WreathProductElem ############################################################################### doc""" - WreathProduct{T<:Group} <: Group -> Implements Wreath product of a group $N$ by permutation (sub)group $P < S_k$, + WreathProduct(N, P) <: Group +> Implements Wreath product of a group `N` by permutation group $P = S_n$, > usually written as $N \wr P$. > The multiplication inside wreath product is defined as -> $$(n, \sigma) * (m, \tau) = (n\psi(\sigma)(m), \sigma\tau),$$ -> where $\psi:P → Aut(N^k)$ is the permutation representation of $S_k$ -> restricted to $P$. +> > `(n, σ) * (m, τ) = (n*σ(m), στ)` +> where `σ(m)` denotes the action (from the right) of the permutation group on +> `n-tuples` of elements from `N` # Arguments: -* `::Group` : the single factor of group $N$ -* `::Generic.PermGroup` : full `PermutationGroup` +* `N::Group` : the single factor of group $N$ +* `P::Generic.PermGroup` : full `PermutationGroup` """ struct WreathProduct{T<:Group, I<:Integer} <: Group N::DirectProductGroup{T} @@ -64,7 +64,11 @@ parent(g::WreathProductElem) = WreathProduct(parent(g.n[1]), parent(g.p)) WreathProduct(G::T, P::Generic.PermGroup{I}) where {T, I} = WreathProduct{T, I}(G, P) -WreathProductElem(n::DirectProductGroupElem{T}, p::Generic.perm{I}, check=true) where {T, I} = WreathProductElem{T, I}(n, p, check) +WreathProduct(G::T, P::Generic.PermGroup{I}) where {T<:AbstractAlgebra.Ring, I} = WreathProduct(AddGrp(G), P) + +WreathProductElem(n::DirectProductGroupElem{T}, p::Generic.perm{I}, check=true) where {T,I} = WreathProductElem{T,I}(n, p, check) + +WreathProductElem(n::DirectProductGroupElem{T}, p::Generic.perm{I}, check=true) where {T<:AbstractAlgebra.RingElem, I} = WreathProductElem(DirectProductGroupElem(AddGrpElem.(n.elts)), p, check) ############################################################################### #