-- | Map the function over the list, and union the results
mapUnionDVarSet  :: (a -> DVarSet) -> [a] -> DVarSet
mapUnionDVarSet get_set xs = foldr (unionDVarSet . get_set) emptyDVarSet xs
mapUnionDVarSet  :: (a -> DVarSet) -> [a] -> DVarSet
mapUnionDVarSet get_set xs = foldr (unionDVarSet . get_set) emptyDVarSet xs
mapUnionDVarSet get_set xs = foldr (unionDVarSet . get_set) emptyDVarSet xs