On 30 October 2016 at 22:37, Kurt Pagani <[email protected]> wrote: > > Am 31.10.2016 um 02:42 schrieb Bill Page: >> On 30 October 2016 at 19:14, Waldek Hebisch <[email protected]> wrote: >>> ... >>> OTOH: >>> >>> (2) -> typeOf(Integer) >>> >>> (2) Type >>> Type: >>> Category >>> (3) -> typeOf(typeOf(Integer)) >>> >>> (3) Category >>> Type: >>> Type >>> (4) -> typeOf(typeOf(typeOf(Integer))) >>> >>> (4) Category >>> Type: >>> Type > > According to the book (0.2.3) there is some logic: > ... The type of every category is the distinguished symbol Category. > > I do interpret this as: Category is a terminal, i.e. has no type at all. > Consequently typeOf(typeOf Type) should not give 'Category' as > result. It's then an almost conceivable fact that Category is a > Symbol whereas Type is not, unless quoted. >
Yes, saying that 'Category' has no type, i.e. that 'typeOf(typeOf Type)' should return 'Failed' seems more sensible to me. In that case what FriCAS actually does is worse than what it appeared to be when typing 'typeOf(Category)' in the interpreter. But I also wonder why 'typeOf(Integer)' is 'Type', i.e. that specific category 'Type'. Why not 'Ring' or some other category that 'Integer' satisfies? -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/fricas-devel. For more options, visit https://groups.google.com/d/optout.
