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

[ijabbott]

(09-07-2018 06:46 PM)compsystems Wrote:  sorry for my bad English

x ≠ -1 should not make a literal comparison x ≠ -1 => 1 synonyms of true, this should leave the symbolic expression, please try the sequence

go to [CAS/settings] Simplify flag: maximum
assume(x,symbol); [enter]
answer:=domain((1/(x+1)),x); returns 1 // the correct output is x ≠ -1

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.