/* 2a"M20 = 2^5:A5 as 10 x 10 monomial matrices over Z. Representation 10a. Absolutely irreducible representation. Schur Index 1. SEED: Nonzero v fixed by x and negated by y*x*y*x*y^-1*x*y^-1 where = 2^5:S3. v has 2 x 10 = 20 images under G; has 10 images under G. BASIS: NSB([x,y]) with above v. Possible matrix entries are in {-1,0,1}. Average number of nonzero entries for any element of the group: 10 (exactly 10%). Entry Av/Mat %Av/Mat 0 90 90 ±1 10 10 1 5 5 -1 5 5 */ F:=Rationals(); G:=MatrixGroup<10,F|\[ 1,0,0,0,0,0,0,0,0,0, 0,0,1,0,0,0,0,0,0,0, 0,-1,0,0,0,0,0,0,0,0, 0,0,0,0,0,1,0,0,0,0, 0,0,0,0,1,0,0,0,0,0, 0,0,0,1,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,1,0, 0,0,0,0,0,0,0,0,0,1, 0,0,0,0,0,0,1,0,0,0, 0,0,0,0,0,0,0,-1,0,0] ,\[ 0,1,0,0,0,0,0,0,0,0, 0,0,0,1,0,0,0,0,0,0, 0,0,0,0,1,0,0,0,0,0, 1,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,1,0,0,0, 0,0,0,0,0,0,0,1,0,0, 0,0,1,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,1,0, 0,0,0,0,0,1,0,0,0,0, 0,0,0,0,0,0,0,0,0,1] >; // Forms: B1 (Symmetric). // B1 (Symmetric form): Determinant 1 [e.divs: 1^6]. B1:=MatrixAlgebra(F,10)!Eltseq(y^3); // Centralising algebra: Scalars only. C1:=MatrixAlgebra(F,10)!Eltseq(y^3);