Jarek Kędra - coauthors:

The Hardy and Littlewood axioms:
  1. When one writes to the other, it is completely indifferent whether what he writes is right or wrong.
  2. When one receives a letter from the other, he is under no obligation to read it, let alone answer it.
  3. Although it does not really matter if we both simultaneously think about the same detail, still it is preferable that we should not do so.
  4. It is quite indifferent if one of us has not contributed the least bit to the contents of a paper under our common name.