Motivated by the recent
concept of a pseudosymmetric braided monoidal category, we define the
pseudosymmetric group PSn to be the quotient of the braid group Bn by the
relations σiσi+1−1σi= σi+1σi−1σi+1 with 1 ≤ i ≤ n − 2. It turns out that PSn is
isomorphic to the quotient of Bn by the commutator subgroup [Pn,Pn] of the pure
braid group Pn (which amounts to saying that [Pn,Pn] coincides with the normal
subgroup of Bn generated by the elements [σi2,σi+12] with 1 ≤ i ≤ n− 2), and that
PSn is a linear group.