let add (candidates: candidates) (candidate: raw_context_unifier) : bool =
  Statistic.inc_computed_assert_candidates candidates.cd_statistic;

  (* store the new candidate for later processing *)
  candidates.cd_unprocessed.(candidates.cd_unprocessed_size) <- candidate;
  candidates.cd_unprocessed_size <- candidates.cd_unprocessed_size + 1;

  build_unprocessed ~force:false candidates