bergmann

Tutorial 5: Valid arguments, searching for a proof

Topic
derivations
propositional
Logical System
bergmann

Tutorial 5. Valid arguments, searching for a proof.

2013

Skills to be acquired in this tutorial:

Proving an argument to be valid by displaying a derivation. Simple propositional derivations using some of the Rules of Inference.

Reading

Bergmann[2004] The Logic Book Section 5.1.

The Tutorial:

If you suspect that an symbolized argument might be valid, you should attempt to give a derivation of it.

A derivation is a proof of validity.

Tutorial 4: Arguments and searching for a counter example

Topic
propositional
Logical System
bergmann

9/16/12

Skills to be acquired in this tutorial:

To learn how to symbolize arguments, and how to judge whether they might be invalid using truth-table methods.

Why this is useful:

We wish to appraise arguments, to do this we have to symbolize them first. Judging the invalidity of arguments by truth-table methods is not particularly important, but it does help to develop skills involving truth and lists of formulas.

Reading

Bergmann[2004] The Logic Book Section 3.5.

Review

Topic
symbolization
propositional
Logical System
bergmann

There is the idea of setting up a code or convention or dictionary between atomic propositions and capital letters.

There are compound propositions, each of which has a main connective which connects its components.

There are five propositional logical connectives:

'∼' which translates back to 'it is not the case that...'

'&' which translates back to '... and ...'

'∨' which translates back to '... or ...'

'⊃' which translates back to 'if... then ...'

'≡' which translates back to '... if and only if ...'

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