Event coreference is largely ignored in works on coreference as well as in works on temporal order in discourses, in which temporal relations between two eventualities e1 and e2 always suppose that e1 6=e2. However, event coreference is not an uncommon phenomenon. We show that it is the keystone on which at least four types of discourses are based: on the one hand, particularizing and generalizing discourses, which can be viewed as special cases of elaboration andreformulation discourses respectively, on the other hand causal discourses in which the effect is expressed by means of a causative verb, which are generally analyzed as explanation or result discourses. Descriptionsand linguistic analyses of these discourses allow us to present unusual linguistic phenomena (e.g., coreference between existentially quantified elements, or assymetrical behavior of explanation or resultdiscourses). The discourse relations involved are examined. This leads us to introduce and define new discourse relations . It also sheds a new light on the discourse relations Explanation and Result.
