Actually, David, I don't quite know why I posted that sentence. :-) I did mean "should be treated as" and in fact you could add to the end of my sentence this: "but they do not actually consider them critical points." I think I was just tired when I was posting, sorry.
Oh, and you are very correct about "should be treated as" and "is." You wouldn't say "Jessie should be treated as a little dog" when you meant to say "Jessie is a little dog," or "the man should be treated as a criminal" compared to "the man is a criminal." :-)
"David W. Cantrell" <DWCantrell@sigmaxi.org> wrote in message news://email@example.com... > Jason Silverman <firstname.lastname@example.org> wrote: > > By the way, my calculus teacher and textbook do teach that the endpoints > > of a segment should be treated as critical points. > > But be careful. To say that Y "should be treated as" X is not quite the > same as saying that Y _is_ X. For this particular case, I've never seen a > text in which endpoints of the domain where actually called critical > points.