22 It is not clear to what use we might put this more detailed information about the varying levels of strength of connection among utterances; however, it parallels the observation in Fais (2001) that some e-mail authors make hierarchical distinctions in marking paragraphs in their messages, using line breaks to separate utterance clusters having some semantic connection and full spaces to separate utterance clusters having weak or no semantic connection.
in our account, utterances that have a coherent relationship to the immediate context of discourse may nonetheless have no Cb; that is, the presence of a Cb is, in our approach, only a sufficient condition.