(sec:4.4)= # Further reading # An introduction to Knowledge Representation can be found in (Ringland & Duce, 1989). (Brachman & Levesque, 1985) is a collection of papers discussing various aspects of Knowledge Representation, such as the difference between isa-links and instance-of-links in semantic networks. Papers about inheritance hierarchies can be found in (Lenzerini *et al.*, 1991). LOGIN is an extension of Prolog in which inheritance is represented by terms rather than clauses (Aït-Kaci & Nasr, 1986). +++ * H. Aït-Kaci & R. Nasr (1986), 'LOGIN: a logic programming language with built-in inheritance', *Journal of Logic Programming* **1986** (3): 185-215. * R.J. Brachman & H.J. Levesque (eds) (1985), *Readings in Knowledge Representation*, Morgan Kaufmann. * M. Lenzerini, D. Nardi & M. Simi (eds) (1991), *Inheritance Hierarchies in Knowledge Representation and Programming Languages*, John Wiley. * G.A. Ringland & D.A. Duce (eds) (1989), *Approaches to Knowledge Representation: an Introduction*, Research Studies Press.