Some Aspects of Analogy in Mathematical Reasoning

An important research problem is the incorporation of “declarative” knowledge into an automated theorem prover that can be utilized in the search for a proof. An interesting proposal in this direction is Alan Bundy’s approach of using explicit proof plans that encapsulate the general form of a proof and is instantiated into a particular proof for the case at hand. We give some examples that show how a “declarative” highlevel description of a proof can be used to find proofs of apparently “similiar” theorems by analogy. This “analogical” information is used to select the appropriate axioms from the database so that the theorem can be proved. This information is also used to adjust some options of a resolution theorem prover. In order to get a powerful tool it is necessary to develop an epistemologically appropriate language to describe proofs, for which a large set of examples should be used as a testbed. We present some ideas in this direction

Developments from enquiries into the learnability of the pattern languages from positive data

AbstractThe pattern languages are languages that are generated from patterns, and were first proposed by Angluin as a non-trivial class that is inferable from positive data [D. Angluin, Finding patterns common to a set of strings, Journal of Computer and System Sciences 21 (1980) 46–62; D. Angluin, Inductive inference of formal languages from positive data, Information and Control 45 (1980) 117–135]. In this paper we chronologize some results that developed from the investigations on the inferability of the pattern languages from positive data

The imperative implementation of algebraic data types

The synthesis of imperative programs for hierarchical, algebraically specified abstract data types is investigated. Two aspects of the synthesis are considered: the choice of data structures for efficient implementation, and the synthesis of linked implementations for the class of ADTs which insert and access data without explicit key. The methodology is based on an analysis of the algebraic semantics of the ADT. Operators are partitioned according to the behaviour of their corresponding operations in the initial algebra. A family of relations, the storage relations of an ADT, Is defined. They depend only on the operator partition and reflect an observational view of the ADT. The storage relations are extended to storage graphs: directed graphs with a subset of nodes designated for efficient access. The data structures in our imperative language are chosen according to properties of the storage relations and storage graphs. Linked implementations are synthesised in a stepwise manner by implementing the given ADT first by its storage graphs, and then by linked data structures in the imperative language. Some circumstances under which the resulting programs have constant time complexity are discussed