中文摘要：

Marek 的前面锁住的构造是为调查非单调的推理的重要技术之一。由在一个逻辑程序上的一致性性质的介绍，他们建议了逻辑程序的一个类， FC 正常的程序，其各个有至少一个稳定模型。然而，怎么为决定一个逻辑程序是否是 FC 正常的选择一个适当一致性性质，不是清楚的。在这篇论文，我们第一发现为任何有限逻辑节目Π，那在那里最不存在一致性性质 LCon (在Π上的Π)，就自己取决于Π ，以便，如果并且仅当Π 是FC正常的关于，Π 是FC正常的( w.r.t ) LCon (Π)。实际上，以便决定一个逻辑程序的 FC 规度，检查单音的补品在 LCon 关上了集合是足够的(为所有非单调的规则的Π) ，那是 LFC (Π) 。第二，我们在场为计算 LFC 的一个算法(Π) 。最后，我们表明为 FC 正常的逻辑程序的勇敢推理任务和小心的推理任务具有象正常逻辑程序的一样的困难。电子增补材料这篇文章(doi:10.1007/s11390-007-9071-1 ) 的联机版本 contatins 增补材料，它对授权用户可得到。

英文摘要：

Marek＇s forward-chaining construction is one of the important techniques for investigating the non-monotonic reasoning. By introduction of consistency property over a logic program, they proposed a class of logic programs, FC-normal programs, each of which has at least one stable model. However, it is not clear how to choose one appropriate consistency property for deciding whether or not a logic program is FC-normal. In this paper, we firstly discover that, for any finite logic programⅡ, there exists the least consistency property LCon（Ⅱ） overⅡ, which just depends onⅡitself, such that, Ⅱ is FC-normal if and only ifⅡ is FC-normal with respect to （w.r.t.） LCon（Ⅱ）. Actually, in order to determine the FC-normality of a logic program, it is sufficient to check the monotonic closed sets in LCon（Ⅱ） for all non-monotonic rules, that is LFC（Ⅱ）. Secondly, we present an algorithm for computing LFC（Ⅱ）. Finally, we reveal that the brave reasoning task and cautious reasoning task for FC-normal logic programs are of the same difficulty as that of normal logic programs.