A bug in the CAS

[wangchong01]

I have found other two bugs
1.function parabola:

Code:

single_inter(line(0,1+i),parabola(0,1))

Then I got "undef". I think it may be due to the undef in the result returned by parabola.
You may try:

Code:

a:=parabola(0,1)
a[2,2]

Then you will get [undef].
The problem still exists in the Xcas 1.2.3.
2.assume
When I assume(x>y), the calculator will not simplify abs(x-y) to x-y, but it will work if I assume x>2 and simplify(abs(x-2)).