ABSTRACT
Throughoutthissection,onestartsfromafinite-dimensionalsimple complexLiealgebraC§<hwithCartansubalgebraGoandrootsystem!Jt0; denotebygao={13 1 ,•••,13n}abasisofsimplerootsofcti0 .Let.;£(v)= C[t1,t]I,...,tv,t;1]bethealgebraofLaurentpolynomialsinthe indeterminatest1 ,•••,tv.
