Step - difference

difference(list) keeps the elements of the list a traverser holds that are not in list. The result is a set: each element at most once, in the order of its first occurrence. Elements compare like dedup() compares traversers (see List Functions).

graphersal> g.V().values("age").fold().difference([27, 29])
[32, 35]

graphersal> g.V().out().out().path().by("name").difference(["ripple"])
[marko, josh]
[marko, josh, lop]

graphersal> g.inject(["a", (), "b"]).difference(["a", "c"])
[null, b]

Rust: difference(vec![27, 29]) and difference_traversal(__::v(None).values("age").fold()).