Equation Icon  BfNLlocal(⃗k ,⃗k ,⃗k ,z) = 2(f P(k )P (k )---ℱ-(⃗k1,⃗k2)--- + cyclicpermutations ). (3.4.3 ) 1 2 3 NL 1 2 D (z)∕D (z = 0)