On Wed, Jun 16, 2021 at 10:41:18PM -0400, Stefan Monnier via Users list for the GNU Emacs text editor wrote:
> >>>> Just to show that you should never say never:
> >>> Hey, that's cheating :-)
> >> Impredicativity is borderline, indeed.
> > Impredicativity, what's that, recursion?
> 
> (with-lecture-mode

:-)

> Kind of, except the cycle is not "definition refers to itself" (the
> "traditional" form of recursion) but rather "definition can be applied
> to itself" as in the first sentence quoted above ;-)

...of that kind "All type theorists shave those philosophers who don't
shave themselves" or some such ;-)

Cheers
 - t