Finding Your Way in a Forest: On Different Types of Trees and Their Properties

Igor Walukiewicz (1)

1 LaBRI - Laboratoire Bordelais de Recherche en Informatique

We see trees in almost any part of computer science. Traditionally, ranked trees, that are nothing else but terms, captured most attention, although exceptions could have been found in graph theory or linguis- tics [9]. Recently unranked trees are a sub ject of renewed interest, mainly because of the developement of XML [22]. It is also quite comon nowadays to see trees with infinite paths, especailly in the context of verification. We will omit this aspect, as for the questions we want to discuss finite trees are sufficiently interesting. We prefer instead to make distinction between ordered and unordered trees, i.e., distinguish situations when syblings are ordered or not. Thus we will deal with four types of trees depending on two parameters: ranked/unranked, and ordered/unordered.

Domaines: Logique en informatique [cs.LO]

Igor Walukiewicz. Finding Your Way in a Forest: On Different Types of Trees and Their Properties. FOSSACS, 2008, Budapest, Hungary. pp.1-4. ⟨hal-00346094⟩