James Every

```elixir property :not_in_suchthat do for_all {x, ys} in such_that({x_, ys_} in {int(), list(int())} when !Enum.member?(ys_, x_)) do assert Enum.member?(ys, x) == false end end ```

We can remove `use ExUnit.Callbacks` from lib/excheck.ex line 14. The test cases must either: ```elixir use ExUnit.Case use ExCheck ``` or ```elixir use ExUnit.Callbacks use ExCheck ```

@evadne I think you should write @maartenJacobs a cheque for £1 ;-) Yes comparing you to Knuth - the reference https://en.wikipedia.org/wiki/Knuth_reward_check

> The pool size default works as well. @maartenJacobs will we be using a pool size of 2 ;-)

@Maria-12648430 Excuse my intrusion, but I have had to deal with a production system that exhausted atoms and it took me weeks to find where it was happening - so...

@Maria-12648430 no worries I guess it just comes down to the fact that the OTP team will be testing "atoms" so they appreciate a broad spectrum of weird and wonderful...