We use a quite concrete and simple realization of $\slq$ involving finite difference operators. We interpret them as derivations (in the non-commutative sense) on a suitable graded algebra, which gives rise to the double of the projective line as the non commutative version of the standard homogeneous space.

1 aFranco, Davide1 aReina, Cesare uhttp://hdl.handle.net/1963/3538