Operations on Reductive Groups

GetSplitPrimeWithSquare(G): GrpRed -> RngIntElt

LowerBound: RngIntElt                    Default: 2

Given a reductive group \(G\) over \({\mathbb{Q}}\), returns a prime \(p\) where \(G_p\) is split, and \(2\) is a square.

Base change

ChangeRing(G, S): GrpRed, Rng -> GrpRed

Given a reductive group \(G\) with base ring \(R\), together with a ring \(S\), construct the reductive group \(G_S\) with base ring \(S\) obtained by coercing the coefficients of elements of \(R\) into \(S\).