{HEAD ~ The catalyst component} comprises {TAIL ~ a magnesium chloride support}, a titanium trichloride, an aluminum trichloride and an organic phosphite 
{ HEAD ~ The catalyst component } comprises { TAIL ~ a magnesium chloride support } , a titanium trichloride , an aluminum trichloride and an organic phosphite
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH