Learn more about this course.

Logical properties and logical relationships

In this article, we review our progress and introduce the ideas of logical properties of sentences and logical relationships between sentences.

We’ve made significant progress so far.

We’ve expanded our formal logical language to include three connectives (ampersand, tilde, and vel). We’ve seen how we can use truth-tables to specify their meanings, and we’ve also see how we can use truth-tables for a number of other tasks (for example, working out the truth-conditions of logically complex sentences, and comparing the truth-conditions of different sentences).

We’ve also looked in some detail at how we can look at the meaning and structure of claims expressed in English, using our formal language as a tool to spell out meaning clearly or (in some cases) say something more clear and precise than what’s said in the original natural language.

At this point we can look at some logical properties of claims, and at logical relationships between claims, and see how we can investigate these and spell them out using truth-tables.