Dear gap-forum, I define a lie algebra which I know to be equivalent to type "A1". I was hoping to have gap calculate a chavalley basis for this, but this doesn't seem to be possible; even though gap recognizes the algebra as "A1" (using SemiSimpleType). Is there a way around this? Thanks, R.N.
mats:= [ [ [ 0, -1, 0 ], [ 1, 0, 0 ], [ 0, 0, 0 ] ], [ [ 0, 0, -1 ], [ 0, 0, 0 ], [ 1, 0, 0 ] ], [ [ 0, 0, 0 ], [ 0, 0, -1 ], [ 0, 1, 0 ] ] ]; alg:=LieAlgebra(Rationals,mats); gap recognizes the algebra as "A1" gap> SemiSimpleType(alg); "A1" but it has trouble with its chevalley basis gap> ChevalleyBasis(alg); Error, no method found! For debugging hints type ?Recovery from NoMethodFound Error, no 1st choice method found for `PositiveRoots' on 1 arguments called fr\ om PositiveRoots( R ) called from <function>( <arguments> ) called from read-eval-loop Entering break read-eval-print loop ... you can 'quit;' to quit to outer loop, or you can 'return;' to continue brk> quit; _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum