著者

Takeuchi Kota Tsuboi Akito

出版者

Elsevier

雑誌

Annals of pure and applied logic (ISSN:01680072)

巻号頁・発行日

vol.163, no.12, pp.1891-1902, 2012-12

被引用文献数

11 5

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We introduce several concepts concerning the indiscernibility of trees. A tree is by definition an ordered set (O,<) such that, for any a∈O, the initial segment {b∈O:b<a} determined by a is a linearly ordered set. A typical example of a tree is the set ω<ω of finite ω-sequences with the order relation <ini, where η<iniν means that η is a proper initial segment of ν. In this paper, we consider some structure M in the language L and are interested in sets A of the form (aη)η∈O, where O is a tree, and aη labeled by η is an element in M. Such a set A is also called a tree in this paper. We study the indiscernibility of trees A in general settings and apply the obtained results to the study of unstable theories.