CAS: 0/0 is undefined, however 1/0 is infinite?

[sasa]

We talking then about "apples and oranges" here...

My point is that here we do not need any trace of extended complex plane, nor complex infinity sign, nor what it actually means - we work here explicitly with set of real numbers.

Thus CAS should be aware of this through many level of settings, which badly missing here... Once again, CAS basically means to use symbolic evaluation, not enabling by default fully all available extended features and deeper analysis, which user probably do not need at all, if not set explicitly...

I will stop then here, since I believe we miss each other points.