Reply to "Comment on `Measurability of nonequilibrium thermodynamics in terms of the Hamiltonian of mean force'"

We refute the criticism expressed in a comment by P. Talkner and P. H"anggi [Phys. Rev. E 102, 066101 (2020)] on our paper Phys. Rev. E 101, 050101® (2020). We first make clear that our paper is free of any technical mistakes. We then defend the statements of our manuscript which were claimed to be taken out of context. Finally, we give clear arguments showing that the basic concepts we rely on are meaningful and have a deep rational.