Exercise 2

I add output and then run it to see it execute.
There is peace of my code with output:

increments([Head | Tail]) -> increments(Head, Tail).

increments(_, []) ->
    io:format("~n"),
    true;
increments(N, [Head | Tail]) when Head == N + 1 ->
    io:format("~p", [Head]),
    if length(Tail) > 0 -> io:format(", ");
       true -> io:format("|")
    end,
    increments(Head, Tail);
increments(_, _) -> false.