May_14 [Compatibility Mode]

# May_14 [Compatibility Mode] - Thursday May 14 ● Today...

This preview shows pages 1–6. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Thursday, May 14 ● Today, we'll talk about: ore logic!- More logic!- 8.7 Common Argument Forms- 8.8 Statement Forms and Material Equivalence- 8.9 Logical Equivalence- 8.10 Three “Laws of Thought”- 9.1 Formal Proof of Validity Review ● Yesterday we looked at the basic structure of logical statements. ● We talked about simple statements and how they, combined with (truth-functional) connectives, make up compound statements. ● We also discussed truth tables, by which we can examine simple statements that comprise compound statements in order to determine such compound statement's validity ● We have, as we went along, discussed translating natural language to symbolic logic. Common Invalid Forms ● Affirming the consequent – p → q; q; Therefore, p enying the antecedent → q; ~p; Therefore, q ● Denying the antecedent – p → q; ~p; Therefore, q ● As stated yesterday, a given argument can be a substitution instance of a number of different argument forms – some of these forms will probably be invalid. The question is whether or not the SPECIFIC form of the argument is valid. Only that form matters. 8.8 Statement Forms ● We've talked about argument forms , where there's only statement variables, and we can sub in statements to make an argument. There are also statement forms , which are comprised of sequences of variables, but no statements. For example: p v q p • q p → q ~q ● All of these are statement forms – the forms of statements but, because they only contain statement variables but no statements, they are not actually compound statements. ● We can substitute in statements as “substitution instances” and we have specific forms Statement Forms (con't) ● So, p • q is the specific form of: Elvis is alive and Elvis is in Vegas. ● And p → q is the specific form of: If it is raining, then the streets will be wet....
View Full Document

## This note was uploaded on 01/08/2010 for the course ME 310 taught by Professor Lwonard during the Spring '09 term at University College Cayman Islands.

### Page1 / 15

May_14 [Compatibility Mode] - Thursday May 14 ● Today...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online