Dear GAP-Forum, dear Alexander Hulpke,
thank you for your suggestion. Now it is possible to compute negative
powers of A but not to work with groups. For instance if I have, as in
my first post,
Indeterminate(Rationals,"x");; p:=UnivariatePolynomial(Rationals,[1,-2,-2,-2,1],1);; e:=FieldExtension(Rationals,p);; t:=RootOfDefiningPolynomial(e); si:=2*t/(1+t2); co:=(1-t2)/(1+t2); idm:=IdentityMat(5,e);; A:=idm*[[0,0,0,0,1], [1,0,0,0,0], [0,1,0,0,0], [0,0,1,0,0], [0,0,0,1,0]];;
and I write
Error, no method found! For debugging hints type ?Recovery from
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
How can I construct groups with matrix like these?
Alexander Hulpke wrote:
Nicola Sottocornola reported some problem with inverting a matrix defined
over an algebraic extension.
This problem stems from the fact that the algebraic extension (in GAP) did
not know that it has no zero divisors. This error will be corrected in the
As a workaround until then, you can read in the attached method into GAP4.3.