In Polchinski's String Theory Vol. 2, equations 10.3.12 are
$$e^{iH(z)}e^{-iH(-z)}~=~\frac{1}{2z}+i\partial H(0)+2zT_B^H(0)+O(z^2)\tag{10.3.12a}$$
$$\psi(z)\bar\psi(-z)~=~\frac{1}{2z}+\psi\bar\psi(0)+2zT_B^\psi(0)+O(z^2)\tag{10.3.12b}$$
How are these two OPEs calculated, especially the second and third terms?
This post imported from StackExchange Physics at 2014-10-15 14:05 (UTC), posted by SE-user Han Yan