He had been bound by an honourable promise not to open any such letters if they did arrive, but to repair to the National Gallery, where his colleague would meet him at ten o'clock.
He opened up and read all the letters.
mnli hypothesis: He opened up and read all the letters. premise: He had been bound by an honourable promise not to open any such letters if they did arrive, but to repair to the National Gallery, where his colleague would meet him at ten o'clock.