 
Summary: Problem Solving in Interactive Proof:
A KnowledgeModelling Approach
James Stuart Aitken
Abstract. This paper presents a model of proof discovery derived
from the proof attempts of subjects who carried out interactive proofs
using the HOL or Isabelle provers. Techniques of knowledge mod
elling, from knowledgebasedsystem development,are usedto derive
a semiformal model of the knowledge utilised by the subjects. The
proposedmodel makesclaims about the relation between the problem
class, the proof plan and its implementation.
1 INTRODUCTION
Automated theorem provers are able to solve increasingly more com
plex problems, however, these tasks still only approximate real world
verification tasks. It is becoming clear that provers developed accord
ing to the automatedproof philosophy will very often require user
intervention to complete a proof. Consequently,the user must attempt
to comprehend the state of a partially successful proof and the repre
sentation of its derivation. The user must then decide how the proof
should be developed.
