import Class ( Class, classTyCon, classSelIds )
import Var ( Id, TyVar, Var, setIdType )
import VarSet ( isEmptyVarSet, subVarSet, varSetElems )
import Class ( Class, classTyCon, classSelIds )
import Var ( Id, TyVar, Var, setIdType )
import VarSet ( isEmptyVarSet, subVarSet, varSetElems )