A context-free grammar is a single-tree grammar (STG) if every nonterminal symbol has at most one production rule whose right hand side contains nonterminal symbols. Various properties of this class of grammars are studied. Although most properties of STG's are undecidable, every linear

We consider the inferability of linear single-tree languages. We are able to show that if the terminal productions of the corresponding grammars obey a simple restriction, then the languages generated are inferable from positive samples only. Moreover, we solve an open problem posed by Greibach

On the basis of regular tree grammars, we present a formal framework for XML schema languages. This framework helps to describe, compare, and implement such schema languages in a rigorous manner. Our main results are as follows: (1) a simple framework to study three classes of tree languages (local

generalizes easily to parsers for augmented phrase structure formalisms, such as definiteclause grammars and other logic grammar formalisms, and has been used for rapid prototyping of parsing algorithms for a variety of formalisms including variants of tree-adjoining grammars, categorial grammars

. Regular tree grammars can be used to generate graphs, by generating expressions that denote graphs. Top-down and bottom-up tree transducers are a tool for proving properties of such graph generating tree grammars. 1 Introduction The most well-known way of generating graphs is to replace a

distributions of supertag co-occurrences collected from a corpus of parses. We have explored these ideas in the context of Lexicalized Tree-Adjoining Grammar (LTAG) framework. The supertags in LTAG combine both phrase structure information and dependency information in a single representation. Supertag

) with regular look-ahead that are single use restricted. For this the single use restriction known from attribute grammars is generalized to MTTs. Since MTTs are closed under regular look-ahead, this implies that every MSO definable tree translation can be realized by an MTT. The second main result

Tree Unification Grammar is a declarative unification-based linguistic framework. The basic grammar staures of this framework arc partial descriptions of trees, and the framework requires only a single grammar rule to combine these partial descriptions. Using this framework, constraints associated

We place synchronous tree-adjoining grammars and tree transducers in the single overarching framework of bimorphisms, continuing the unification of synchronous grammars and tree transducers initiated by Shieber (2004). Along the way, we present a new definition of the tree-adjoining grammar

), where occ is the number of occurrences of P in S. Finally, we are able to generalize our results to navigation and other operations on grammar-compressed trees. All of the above bounds significantly improve the currently best known results. To achieve these bounds, we introduce several new techniques