altTyCons :: CoreAlt -> Set TyCon
altTyCons (alt,_,rhs) = patTyCons alt `S.union` exprTyCons rhs
altTyCons :: CoreAlt -> Set TyCon
altTyCons (alt,_,rhs) = patTyCons alt `S.union` exprTyCons rhs
altTyCons (alt,_,rhs) = patTyCons alt `S.union` exprTyCons rhs