Hi!
Let us consider the number
a=1/sqrt(4-2*sqrt(3))-1/(sqrt(3)-1)
which is zero. If we simplify
a.simplify_full().n()
we obtain
-2.73205080756888 - 8.36449319149292e-17*I,
which of course is false. I guess it is a problem handling complex roots of degree four, but still, it don't seems to me a reasonable computation. ¿Anybody knows how to fix it?