All possible graded Poisson-Lie structures on the external algebra of
SL(2) are described. We prove that differential Poisson-Lie structures
prolonging the Sklyanin brackets do not exist on SL(2). There are two
and only two graded Poisson-Lie structures on SL(2) and neither of th
em can be obtained by a reduction of graded Poisson-Lie structures on
the external algebra of GL(2). Both of them can be quantized and as a
result we get new graded algebras of quantum right-invariant forms on
SL(q)(2) with three generators. (C) 1994 American Institute of Physics
.