Evaluating Undefined expressions?

[Han]

(11-06-2015 07:01 PM)Spybot Wrote:  Hp Prime CAS; says "zero" make this inequality a true statement, while WolframAlpha doesn't include "zero" in the number line, just like the HP Prime Function App suggests graphically.
Too many contradictions.
As Parisse said: "CAS is correct." I also agree with that... I just wish CAS and HOME converge one day in situations like this!

I suppose contradictions would be the appropriate term here since it is unclear whether we are working over just real numbers or over the extended reals (i.e. the real numbers extended with \( \infty \)). In the former, undefined would be the correct result. And in the latter, 1 would be the correct result. In Home view, everything is "numerical" in that all terms must be known numerically. Even variables -- if they exist, their value is whatever we assign, or 0 by default. As for \( \infty \), that's not a number -- it's more of a concept, in my opinion. However, in the CAS view, we are allowed to have symbols (undefined variables) and by extension, the CAS would also be able to handle \( \infty \) in the same manner that it is able to handle the variable \( x \) even if no value is stored.