Kauffman bracket ($⟨D⟩$)

The Kauffman bracket is the unoriented diagram invariant determined by resolving each crossing into its two smoothings and replacing every additional disjoint circle by the loop factor $-A^2-A^{-2}$. It is invariant under the second and third Reidemeister moves.

The Jones polynomial is obtained from the Kauffman bracket of an oriented diagram by the writhe normalization