What knot would you use here?

I am reading George Daniel's book "Dynamic Nymphing" and in chapter 2 he gives a few different examples of leader setups. Could someone please tell me which is the correct type of knot to use to attach the piece of 4-5" tippet that the first nymph hangs off? I am sure there is a correct knot to use that won't slide and won't create a weak point on the main piece of fluorocarbon, but I am inexperienced with this setup. Thanks in advance