Finbarr Timbers

Hey folks- I was also confused by this, so I [wrote up the derivation](https://finbarr.ca/deriving-the-dall-e-lower-bound/). I'd appreciate a second check over my math.

FWIW, I'm on 10.10.4, using Tmux 2.0, and reattach-to-user-namespace 2.4, and I periodically run into the same issue; restarting the Tmux server fixes the issue.