Absolute value: sometimes CAS is very clever, sometimes not!

[ijabbott]

(09-08-2018 04:38 AM)Joe Horn Wrote:  

(09-08-2018 03:37 AM)ijabbott Wrote:  So if I understand correctly, you want to be able to store a symbolic value (of type DOM_SYMBOLIC) in a variable? That would be a nice feature. I haven't studied Xcas/Giac as much as you, but I think the closest you can get to your desired result at the moment is to store it as a string (type DOM_STRING) by using the cat() function. E.g.: answer:=cat(domain((1/(x+1)),x)). But I don't know how to convert it back to a symbolic value.

You can store any object type into any CAS variable:

Hi Joe,

But can you store a symbolic value such as the return value of the domain() function into a variable without the return value being evaluated? E.g. domain((1/(1+x),x) returns 'x ≠ -1', but if you try to store it, it gets evaluated as 1 or 'true' (assuming 'x' is purged or symbolic).