问题描述
在已知论文中,FLP(Fisher,Lynch和Paterson)证明了令人惊讶的结果,即即使一个未经通知的进程死亡,也没有完全异步的共识协议可以容忍。
In the known paper Impossibility of Distributed Consensus with one Faulty Process (JACM85), FLP (Fisher, Lynch and Paterson) proved the surprising result that no completely asynchronous consensus protocol can tolerate even a single unannounced process death.
在引理3中,显示D包含0和1价配置后,它说:
In Lemma 3, after showing that D contains both 0-valent and 1-valent configurations, it says:
如果一个配置在另一个 step 中产生,则调用两个配置 neighbors 。通过简单的归纳法,存在邻居C₀,C₁∈C,使得Dᵢ= e(Cᵢ)为i价,i = 0,1。
我可以遵循整个证明,除非他们声称存在这样的C₀和C follow。你能给我一些提示吗?
I can follow the whole proof except when they claim the existence of such C₀ and C₁. Could you please give me some hints?
推荐答案
D
(应用<$ c之后的可能配置集$ c> e 到 C
的元素都包含0-价和1-价配置(并且假定不包含二价配置)。
D
(the set of possible configurations after applying e
to elements of C
) contains both 0-valent and 1-valent configurations (and is assumed to contain no bivalent configurations).
即- e
映射 C
中的每个元素变为0价或1价构型。根据 C
的定义,必须有一个通过一系列邻居关系连接到所有其他元素的根元素,因此,必须是一个边界点,其中 C
中的一个元素在 e
与元素相邻之后导致0价配置在 C
中导致 e
之后为一价配置。
That is — e
maps every element in C
to either a 0-valent or a 1-valent configuration. By definition of C
, there must be a root element that is connected to all other elements by a series of "neighbour" relationships, so there must be a boundary point where an element in C
that leads to a 0-valent configuration after e
is neighbours with an element in C
that leads to a 1-valent configuration after e
.
这篇关于FLP不可能结果证明中存在0和1价结构的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!