On Sun, Dec 16, 2018 at 3:07 AM Waldek Hebisch <hebi...@math.uni.wroc.pl> wrote: > Well, in FriCAS tree is an aggregate. And empty aggregate > is always legal. In fact, empty aggregate is a generic > way to start building an aggregate. So disallowing it > does not look right.
For Tree, can I commit the patch with: empty_tree := [NIL$Lisp, []] empty() == empty_tree empty? t == eq?(t, empty_tree) I still don't think "empty()" is essential to aggregate. It is useful sometimes to define aggregate with fixed size, for such aggregate, "empty()" is illegal. -- You received this message because you are subscribed to the Google Groups "FriCAS - computer algebra system" group. To unsubscribe from this group and stop receiving emails from it, send an email to fricas-devel+unsubscr...@googlegroups.com. To post to this group, send email to fricas-devel@googlegroups.com. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.