All this ensures that if an op gets broadcasted through the mempool, then it is guaranteed that that op can get included on-chain and will pay fees - unless another op from that same account gets in first. Like Ethereum txs today.
All this prevents DoS attacks on the mempool.
所有这一切都确保了如果一个操作通过内存池广播，那么可以保证该操作可以被包含在链上并支付费用——除非来自同一账户的另一个操作首先进入。就像今天的以太坊 txs。
所有这些都可以防止对内存池的 DoS 攻击。