Operations on Group Representations

Contents

Intersection(V, W) : ModRed, ModRed -> ModRed
V meet W : ModRed, ModRed -> ModRed
If V, W ⊆U are both subrepresentations of U, return the intersection V ∩W ⊆U.
V eq W : ModRed, ModRed -> BoolElt
V eq W : CombFreeMod, CombFreeMod -> BoolElt
Returns true if the representations V and W are equal; otherwise false

Base Change

ChangeRing(V, S) : ModRed, Rng -> ModRed
The group representation VS = V tensor R S with base ring changed to S.
ChangeRing(M, S) : CombFreeMod, Rng -> CombFreeMod
The module MS = M tensor R S with base ring changed to S.

Other Operations

FixedSubspace(H, V) : GrpMat, ModRed -> ModRed
Given a subgroup H ⊆G, returns the subspace VH, the vectors of V fixed by H.
V2.29, 21 October 2025