  Douglas-Rachford method is a splitting algorithm for finding a zero of the
sum of two maximal monotone operators. Weak convergence in this method to a
solution of the underlying monotone inclusion problem in the general case
remained an open problem for 30 years and was prove by the author 7 year ago.
The proof presented at that occasion was cluttered with technicalities because
we considered the inexact version with summable errors. The aim of this note is
to present a streamlined proof of this result.
