(07-18-2018 08:31 PM)BartDB Wrote: (07-18-2018 04:05 PM)Vtile Wrote: (a/b)/(a/b) = 1

...

(2a/b)*(b/a) = 2

Not for all values of a and b.

More generally \(\frac{x}{x}= 1\: for \: all \:x\neq 0\)

The discontinuities must always be excluded. For example in equations with fractions, the points where the denominator(s) = 0 must be excluded (have exception handling).

Yes you are correct many such cases done with proper accepted rules (edit. btw. again exception in definition), but iirc isn't NaN (as infinity many results/logic brakepoint/undefined infinity)* and +-inf (numerical infinity)* and +-0 (infinitesimals/zero as inverse of infinity) used for such to continue the analysis in logical way.

*as I see/understand them.