/base

• Base doesn't support relative complement of topic.
  • ex)

    ADD [A0]
    DEL [A0 B0 C0] - this request will be ignored.
    result: [A0]
    

• Base supports union of topic.
  • ex)

    ADD [A0 B0 C0]
    ADD [A0]
    result: [A0] - B0 and C0 is truncated.