and (if R is invertible) a representation of the braid group, B n , can be constructed on V ⊗ ⊗ n by σ σ i = 1 ⊗ ⊗ i − − 1 ⊗ ⊗ R ˇ ˇ ⊗ ⊗ 1 ⊗ ⊗ n − − i − − 1 for i = 1 , … … , n − − 1 . This representation can be used to determine quasi-invariants of braids, knots and links.