ProCGroups.FoxDifferential.Discrete.FoxCalculus.Semidirect
The principal declarations in this module are:
RelativeFreeFoxCoordinatesFox-coordinate vectors for a homomorphism from a free group to a target group \(H\). The coefficients are already pushed forward to \(\mathbb{Z}[H]\); this is the coordinate module which will identify \(A_{\psi}\) with \(\mathbb{Z}[H]^X\) for \(\psi:\mathrm{FreeGroup}(X)\to H\). -RelativeFoxActionThe canonical group-ring scalar action ofHon relative Fox-coordinate vectors.
abbrev RelativeFreeFoxCoordinates : Type _ := X → GroupRing HFox-coordinate vectors for a homomorphism from a free group to a target group \(H\). The coefficients are already pushed forward to \(\mathbb{Z}[H]\); this is the coordinate module which will identify \(A_{\psi}\) with \(\mathbb{Z}[H]^X\) for \(\psi:\mathrm{FreeGroup}(X)\to H\).
Abbreviation
FoxDifferential.FoxCalculus.RelativeFoxAction
abbrev RelativeFoxAction :
H →* Multiplicative (AddAut (RelativeFreeFoxCoordinates (H := H) X)) :=
scalarCrossedAction (A := RelativeFreeFoxCoordinates (H := H) X)
(groupRingScalar (MonoidHom.id H))The canonical group-ring scalar action of H on relative Fox-coordinate vectors.