unifyPredicates :: (a -> Set.Set NAME) -> [a] -> Set.Set NAME
unifyPredicates prd_item = foldl (\ns i -> Set.union ns (prd_item i)) Set.empty
unifyPredicates :: (a -> Set.Set NAME) -> [a] -> Set.Set NAME
unifyPredicates prd_item = foldl (\ns i -> Set.union ns (prd_item i)) Set.empty
unifyPredicates prd_item = foldl (\ns i -> Set.union ns (prd_item i)) Set.empty