Hi,

what is the proper way of dealing with negative infinity in STACK? Maxima is providing the symbol minf for limits and if I use ta: limit(-x^3,x,inf) to calculate a correct answer the student will be told to type this answer as minf. The expression -inf (despite of looking exactly the same in the validation) won't be accepted (with answer test AlgEquiv).

On the other hand when dealing with intervals -inf is occuring as well. E.g. natural_domain(sqrt(-x)) evaluates to realset(x,oc(-inf,0)).

Is there a robust way to just use one or the other? I think it can be really confusing for students, especially if two different syntaxes would occure in the same question.

Stephan.