Computation tree logic

线性时序逻辑（英語：linear temporal logic，LTL），或称线性时态逻辑，是一种模态时态逻辑。其时态运算符限定于描述从一个给定的状态开始的某一条路径上的事件。线性时序逻辑由阿米尔·伯努利在1977年提出。线性时序逻辑和计算树逻辑（英语：Computation tree logic）两者可以归入更广义的CTL*（英语：CTL*）中。

new_tree_list = [] for tree in tree_list: if tree is not None: yield tree.value new_tree_list.append(tree.left) new_tree_list.append(tree.right) tree_list

Courcelle, B., The monadic second-order logic of graphs I: Recognizable sets of finite graphs, Information and Computation, 1990, 85: 12–75, CiteSeerX 10.1.1

the environment structure be potentially tree-like. Finally, the environment at any point in a computation can never be deeper than the lexical depth

Turner, J. S., The vertex separation and search number of a tree, Information and Computation, 1994, 113 (1): 50–79, doi:10.1006/inco.1994.1064  . Feige