INFERRING UNIONS OF TWO PATTERN LANGUAGES

Characteristic Sets for Inferring the Unions of the Tree Pattern Languages by the Most Fitting Hypotheses

A tree pattern p is a first-order term in formal logic, and the language of p is the set of all the tree patterns obtainable by replacing each variable in p with a tree pattern containing no variables. We consider the inductive inference of the unions of these languages from positive examples using strategies that guarantee some forms of minimality during the learning process. By a result in ou...

On Learning Unions of Pattern Languages and Tree Patterns

Two-dimensional pattern languages

We introduce several classes of array languages obtained by generalising Angluin’s pattern languages to the two-dimensional case. These classes of two-dimensional pattern languages are compared with respect to their expressive power and their closure properties are investigated.

Inferring Deterministic Linear Languages

Linearity and determinism seem to be two essential conditions for polynomial language learning to be possible. We compare several definitions of deterministic linear grammars, and for a reasonable definition prove the existence of a canonical normal form. This enables us to obtain positive learning results in case of polynomial learning from a given set of both positive and negative examples. T...

A Polynomial Time Algorithm for Finding Finite Unions of Tree Pattern Languages

A tree pattern is a structured pattern known as a term in formal logic, and a tree pattern language is the set of trees which are the ground instances of a tree pattern. In this paper, we deal with the class of tree languages whose language is de ned as a union of at most k tree pattern languages, where k is an arbitrary xed positive number. In particular, we present a polynomial time algorithm...