If there are serious doubts as regards the possibility of performing the invention and repeating it as described, the burden of proof as regards this possibility, or at least a demonstration that success is credible, rests with the applicant, who can discharge this burden of proof during the PCT Chapter II procedure or after entry into the European phase before the EPO. As regards the possibility of performing and repeating the invention, see also GL/PCT‑EPO F‑III, 3.