Hi! > 2. Also, I don't understand the behaviour of the > > IsAlgebraWithOne( algebra ) > > function. For example, I have defined > > gap> A := FullMatrixAlgebra( Rationals, 3 ); > ( Rationals^[ 3, 3 ] ) > > This is an algebra with One( A ) = [ [1,0,0], [0,1,0], [0,0,1]]. However, > when I construct the direct S = sum A \otimes A by > > gap> S := DirectSumOfAlgebras( A, A ); > <algebra over Rationals, with 6 generators> > > This has the unit > > gap> One( S ); > [ [ 1, 0, 0, 0, 0, 0 ], [ 0, 1, 0, 0, 0, 0 ], [ 0, 0, 1, 0, 0, 0 ], [ 0, 0, > 0, 1, 0, 0 ], [ 0, 0, 0, 0, 1, 0 ], > [ 0, 0, 0, 0, 0, 1 ] ] > > however, IsAlgebraWithOne( S ) is returning false: > > gap> IsAlgebraWithOne( S ); > false > > Sincerely, Sandeep.
It's just this kind of things that surpise me as well. In one of my earlier posts a few days ago I stated that ListX(Combinations(a,2),Combinations(a,2),\>,pair); works but ListX(Combinations(a,2),Combinations(a,2),\<,pair); doesn't. (of course a and pair are defined separately) Which is unlogical as well. Your IsAlgebraWithOne(S); should be true of course. Gap isn't perfect. Sincerely, Lisette _______________________________________________ Forum mailing list [email protected] http://mail.gap-system.org/mailman/listinfo/forum
