Implicit relations in the PDTB are only ever annotated between consecutive sentences.
we specifically extract pairs of consecutive sentences on the source English side: • that are identified as the Arg1 and Arg2 of an implicit discourse relation 1 ; • whose corresponding back-translated target sentences are identified as the Arg1 and Arg2 of an explicit relation; • that are not part of the Arg1 or Arg2 of any other discourse relations 2 .