2012 | OriginalPaper | Chapter

# 8. Yea and Nay: Propositional Logic

Published in:
Sets, Logic and Maths for Computing

## Abstract

We have been using logic on every page of this book – in every proof, verification and informal justification. In the first four chapters, we inserted some ‘logic boxes’; they gave just enough to be able to follow what was being done. Now we gather the material of these boxes together and develop their principles. Logic thus emerges as both a tool for reasoning and an object for study.

We begin by explaining different ways of approaching the subject and situating the kind of logic that we will be concerned with, then zooming into a detailed account of classical propositional logic. The basic topics there will be the truth-functional connectives, the family of concepts around tautological implication, the availability of normal forms and unique minimalities for formulae and the use of semantic decomposition trees as a shortcut method for testing logical status.