"It follows easily from the bracket skein relation that a closed curve must count for a factor $\delta = −A^2 − A^{−2}$"
Given the skein relation $< \times>=A<\, )(\, > + A^{-1}< \, \asymp \, >$, I don't understand how they have gotten this result. Can anyone explain?
Also, this quote is from the notes at https://math.berkeley.edu/~vfr/jonesakl.pdf
This quantity is choosen in such a way that the Kauffman bracket is invariant under the second Reidemeister move. I does not follow from the skein relation alone.