> > 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. > > Regarding \< and \>: it is a > b if and only if b < a, so GAP needs only > one of the operations \<, \>. If both operations would exist, always for both > of them methods would need to be installed -- one of them just 'for nothing'.
I hope you don't mind that I write a reply on this again. What doesn't work either is: a:=[1,2,3,4]; pair:=function(x,y); return[x,y]; end; > ListX(Combinations(a,2),Combinations(a,2),\<\>,pair) So I tried: not ListX(Combinations(a,2),Combinations(a,2),\=,Pair) which leads to: Variable: 'Pair' must have a value. [I am still surprised about this, because /> does work (As already asked and answered upon.] So, \< isn't entirely "for nothing" because now "\<\>" doesn't work either. And using "not" isn't a solution for that. Or am I seeing this wrongly? Best regards, Lisette _______________________________________________ Forum mailing list Forum@mail.gap-system.org http://mail.gap-system.org/mailman/listinfo/forum
