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第220行：
第220行： − 第一种情况有时被称为严格的纳什均衡点。第二种情况有时被称为“梅纳德 · 史密斯的第二种情况”。第二个条件意味着尽管策略 t 相对于策略 s 的收益是中性的，但是继续使用策略 s 的玩家在对抗策略 t 时有优势。+ − 第228行：
第227行： − 由于托马斯的缘故，还有另一种更强有力的 ESS 定义。这就不同程度地强调了纳什均衡点概念在斯洛文尼亚就业服务系统中的作用。根据上面第一个定义中给出的术语，这个定义要求对于所有 t ≠ s+ + + − − − # E(''S'',''S'') ≥ E(''T'',''S''), '''and''' − − E(S,S) ≥ E(T,S), and − − E(S,S) ≥ E(T,S), and − − # E(''S'',''T'') > E(''T'',''T'') − − E(S,T) > E(T,T) − − E (s，t) > e (t，t) 第250行：
第238行： − 在这个公式中，第一个条件指定策略是纳什均衡点，第二个条件指定 Maynard Smith 的第二个条件是满足的。请注意，这两个定义并不完全等价: 例如，下面协调博弈中的每个纯策略按照第一个定义都是 ESS，但不是第二个定义。+ − 第258行：
第245行： − 换句话说，这个定义是这样的: 当第一个参与人同时使用策略 s 时，第一个参与人改用另一个策略 t 时，第一个参与人的收益大于(或等于)第一个参与人改用策略 t 时的收益，第二个参与人保留策略 s 时的收益，第一个参与人改用策略 t 时的收益大于第一个参与人改用策略 t 时的收益。+ 第266行：
第253行： − 这个公式更清楚地强调了纳什均衡点条件在斯洛文尼亚就业服务系统中的作用。它还允许相关概念的自然定义，如弱 ESS 或进化稳定集。+
→Nash equilibrium
The first condition is sometimes called a strict Nash equilibrium. The second is sometimes called "Maynard Smith's second condition". The second condition means that although strategy T is neutral with respect to the payoff against strategy S, the population of players who continue to play strategy S has an advantage when playing against T.
The first condition is sometimes called a strict Nash equilibrium. The second is sometimes called "Maynard Smith's second condition". The second condition means that although strategy T is neutral with respect to the payoff against strategy S, the population of players who continue to play strategy S has an advantage when playing against T.
第一个条件有时称为严格的纳什平衡。而第二个有时称为“梅纳德·史密斯的第二个条件”，它意味着，尽管策略T在对抗策略S时收益不变，但继续使用策略S的玩家在对抗策略T时收益具有明显优势。
There is also an alternative, stronger definition of ESS, due to Thomas. This places a different emphasis on the role of the Nash equilibrium concept in the ESS concept. Following the terminology given in the first definition above, this definition requires that for all T≠S
There is also an alternative, stronger definition of ESS, due to Thomas. This places a different emphasis on the role of the Nash equilibrium concept in the ESS concept. Following the terminology given in the first definition above, this definition requires that for all T≠S
后来伯恩哈德·托马斯Bernhard Thomas在他的论文《On evolutionarily stable sets》中提出了更大胆的定义。它不同于纳什平衡概念在进化均衡策略中的作用。根据上面第一个定义中给出的术语，此处要求对所有T≠S：
1. E(S,S) ≥ E(T,S)，并且
2. E(S,T) > E(T,T)，
In this formulation, the first condition specifies that the strategy is a Nash equilibrium, and the second specifies that Maynard Smith's second condition is met. Note that the two definitions are not precisely equivalent: for example, each pure strategy in the coordination game below is an ESS by the first definition but not the second.
In this formulation, the first condition specifies that the strategy is a Nash equilibrium, and the second specifies that Maynard Smith's second condition is met. Note that the two definitions are not precisely equivalent: for example, each pure strategy in the coordination game below is an ESS by the first definition but not the second.
在这两个公式中，第一个指定了该策略采取纳什平衡，而第二则是指定满足梅纳德·史密斯的第二个条件。请注意，这两个定义并不完全相等：例如，在接下来的协调游戏中的每个独立策略都是第一个定义的进化均衡策略，而非第二个。
In words, this definition looks like this: The payoff of the first player when both players play strategy S is higher than (or equal to) the payoff of the first player when he changes to another strategy T and the second player keeps his strategy S and the payoff of the first player when only his opponent changes his strategy to T is higher than his payoff in case that both of players change their strategies to T.
In words, this definition looks like this: The payoff of the first player when both players play strategy S is higher than (or equal to) the payoff of the first player when he changes to another strategy T and the second player keeps his strategy S and the payoff of the first player when only his opponent changes his strategy to T is higher than his payoff in case that both of players change their strategies to T.
换句话说，此定义还可以这么理解，当两个玩家都玩策略S时：1. 第一个玩家的收益要高于（或等于）当第一个玩家更改为策略T而第二个玩家保持策略S时的收益。2. 当第一个玩家的对手将策略更改为T时，第一个玩家自身的收益要大于他们两者都更改为策略T。
This formulation more clearly highlights the role of the Nash equilibrium condition in the ESS. It also allows for a natural definition of related concepts such as a weak ESS or an evolutionarily stable set.
This formulation more clearly highlights the role of the Nash equilibrium condition in the ESS. It also allows for a natural definition of related concepts such as a weak ESS or an evolutionarily stable set.
这种表述更清楚地强调了纳什平衡条件在进化均衡策略中的作用。同时还考虑到对相关概念进行自然定义，例如弱进化均衡策略Weak evolutionarily stable strategy或进化均衡集合Evolutionarily stable set。