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Unifying Theories of Undefinedness

Lookup NU author(s): Dr Leo Freitas


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We propose a unifying theory of undefined expressions in logics used for formally specifying software systems. We show how to use classical logic to prove facts in a monotonic partial logic with guards, and we exhibit guards for several different semantical systems. We show how classical logic can be used to prove semi-classical facts. The mechanical theorem prover Z/Eves is used to prove facts about semi-classical Z specifications, although it uses classical logic; it does this with guards from McCarthy logic. It can also be used to prove facts about VDM specifications. The use of left-to-right guards guarantees, for example, that every theorem proved in Z/Eves is valid in VDM and in Z.

Publication metadata

Author(s): Woodcock J, Saaltink M, Freitas L

Editor(s): Broy, M., Sitou, W., Hoare, T.

Publication type: Book Chapter

Publication status: Published

Book Title: Engineering Methods and Tools for Software Safety and Security

Year: 2009

Volume: 22

Pages: 311-330

Series Title: NATO Science for Peace and Security Series - D: Information and Communication Security

Publisher: IOS Press

Place Published: Amsterdam


DOI: 10.3233/978-1-58603-976-9-311

Notes: Online ISBN: 9781607504108

Library holdings: Search Newcastle University Library for this item

ISBN: 9781586039769