+/** \brief Find a suitable subrange of candidate duplicates for a given state
+ *
+ * \param all_ pairs dynamic array of states with candidate duplicates of the current state;
+ * \param pair current state;
+ * \param min (output) index of the beginning of the the subrange
+ * \param max (output) index of the enf of the subrange
+ *
+ * Given a suitably ordered array of state, this function extracts a subrange
+ * (with index *min <= i <= *max) with candidate duplicates of the given state.
+ * This function uses only fast discriminating criterions and does not use the
+ * full state comparison algorithms.
+ *
+ * The states in all_pairs MUST be ordered using a (given) weak order
+ * (based on nb_processes and heap_bytes_used).
+ * The subrange is the subrange of "equivalence" of the given state.
+ */