### Abstract

This paper reports on an investigation into a formal language for specifying KADS models of expertise. After arguing the need for and the use of such formal representations, we discuss each of the layers of a KADS model of expertise in the subsequent sections, and define the formal constructions that we use to represent the KADS entities at every layer: order-sorted logic at the domain layer, meta-logic at the inference layer, and dynamic-logic at the task layer. All these constructions together make up (ML)^2, the language that we use to represent models of expertise. We illustrate the use of (ML)2 in a small example model. We conclude by describing our experience to date with constructing such formal models in (ML)2 , and by discussing some open problems that remain for future work.

Original language | English |
---|---|

Title of host publication | KADS: A Principled Approach to Knowledge-Based System Development |

Pages | 127-161 |

Publication status | Published - 1992 |

### Bibliographical note

Harmelen, F.A.H. van and J. R. Balder. (ML)2: a formal language for KADS models of expertise. Volume 4. Pages 127-161. 1992. Special issue: `The {KADS} approach to knowledge engineering', reprinted in KADS: A Principled Approach to Knowledge-Based System Development}, 1993, Schreiber, A.Th. et al. (eds.). Journal Knowledge Acquisition Journal. Number 1.## Fingerprint Dive into the research topics of '(ML)2: a formal language for KADS models of expertise'. Together they form a unique fingerprint.

## Cite this

van Harmelen, F. A. H., & Balder, J. R. (1992). (ML)2: a formal language for KADS models of expertise. In

*KADS: A Principled Approach to Knowledge-Based System Development*(pp. 127-161)