[GAP Forum] Simple matrix group

[Nicola Sottocornola]

Hi,

can you help with this very simple code? It produces an error msg.

Thanks, Nicola


***************************

LoadPackage("singular");

F:=Rationals;
R:=PolynomialRing( F, ["x","y","z","w"]);
SetTermOrdering( R, [ "wp", [1,1,2,2] ] );
SingularSetBaseRing(R);

A := [
[-1,0,0,0],
[0,1,0,0],
[0,0,-1,0],
[0,0,0,1]
] * One(R);

B := [
[-1,0,0,0],
[0,-1,0,0],
[0,0,-1,0],
[0,0,0,-1]
] * One(R);

C := [
[0,1,0,0],
[1,0,0,0],
[0,0,0,1],
[0,0,1,0]
] * One(R);

G:=Group(A,B,C);

******************************

gap> G;
<matrix group with 3 generators>
gap> Size(G);
Error, no method found! For debugging hints type ?Recovery from  
NoMethodFound
Error, no 2nd choice method found for  
`GeneratorsOfLeftOperatorRingWithOne' on 1 arguments called \
from
GeneratorsOfLeftOperatorRingWithOne( A ) called from
GeneratorsOfLeftOperatorRing( A ) called from
Basis( V ) called from
Enumerator( D ) called from
Field( fg ) called from
...
Entering break read-eval-print loop ...
you can 'quit;' to quit to outer loop, or
you can 'return;' to continue
brk>