Stéfane Fermigier wrote: > On Wed, Mar 4, 2020 at 8:24 AM Steve Jorgensen ste...@stevej.name wrote: > > Chris Angelico wrote: > > On Wed, Mar 4, 2020 at 6:04 PM Steve Jorgensen > > ste...@stevej.name wrote: > > <snip> > > https://en.wikipedia.org/wiki/Partially_ordered_set > > "Partially ordered" means you can compare pairs of elements and find > > which one comes first. "Totally ordered" means you can compare ANY > > pair of elements, and you'll always know which comes first. > > ChrisA > > Ah. Good to know. I don't think "Partially ordered" actually applies, > > then, because that still seems to imply that transitivity would apply to > > comparisons between any given pair of objects. Simply having > > implementations of all the rich comparison operators does not make that > > true, however, and in particular, that's not true for sets. > > Not quite: https://en.wikipedia.org/wiki/Partially_ordered_set#Examples > (see > example 2). > Or: > https://math.stackexchange.com/questions/1305004/what-is-meant-by-ordering-o... > S.
Ah! That Wikipedia article is very helpful. I see that it is not necessary for all items in a partially ordered set to be comparable. Taking one step back out of the realm of mathematical definition, however, the original idea was simply to distinguish what I now understand to be "totally ordered" types from other types, be they "partially ordered" or unordered — not even having a full complement of rich comparison operators or having all but using them in weirder ways than sets do. _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/S6VZ4DWZBL3NLBFZKJYPN5EE5OMRAF3V/ Code of Conduct: http://python.org/psf/codeofconduct/
