PPT-Contradiction

In classical logic a contradiction consists of a logical incompatibility between two or more propositions It occurs when the propositions taken together yield two conclusions which form the logical usually opposite inversions of each other Illustrating a general tendency in applied logic . These three techniques are used to prove statements of the form If then As we know most theorems and propositions have this conditional form or they can be reworded to have this form Thus the three main techniques are quite important But some theo brPage 3br Validity for argument forms Truth tables for argument forms Homework Philosophy 205 Symbolic Logic Lecture 6 Truth tables and arguments Geo64256 Pynn Northern Illinois University Spring 2012 brPage 4br Validity for argument forms Truth ta Thisisapowerfulpro oftechnique that can be extremely useful in the right circumstances Well need this method in Chapter 20 when we cover the topic of uncountability Ho wever contradiction proofs tend to be less convincing and harder to write than di Philosophy 220 and Contingency Review  A sentence in natural language is logically true if and only if it cannot (logically) be false. (Tautology)  A sentence in natural language i the barber. The Barber Paradox. Once upon a time there was a village, and in this village lived a barber named B. . B shaved . all. the villagers who did . not. shave themselves, . And B shaved . none. ISSN 0267-7091 ISBN 1 85637 336 3www.libertarian.co.uk email: admin@libertarian.co.uk Proofs that K5 and K3,3 . are not planar. Copyright © R F Barrow 2009, all rights reserved. www.waldomaths.com. K. 5. K. 3,3. The Proofs that K. 5. and K. 3,3. are not planar. Complete graph with 5 nodes. I. I. PROPOSISI. 2. Tautology and Contradiction. Definition. A tautology . is a statement . form that is always true.. A statement whose form is . a tautology is a tautological . statement. . A contradiction .   THE COLOR SQUARE . GAME. Objective:.  Figure out the arrangement of colored squares on a 3 × 3 grid or a 4 × 4 grid using as few clues as possible. .. Rules. :.  In a 3 × 3 Color Square Game, each of the nine squares are colored: three are red, three are green, and three are blue. However, all squares of the same color must be contiguous (linked along a side). The diagram below demonstrates what is meant by contiguous.. Dr. Yasir Ali. Two . statement forms . are called . logically equivalent . if, and only if, they have . identical truth . values for each possible substitution of statements for their statement variables. Announcements. No Class, Monday, 11-Nov-2013. Work on project. Device demonstration 10. th. week (13-Nov) during lab:. Final Exam, Wednesday, 20-Nov. at 6:00 PM. O231 – Section 01. O233 – Section 02. Proving a Language is Not Regular. Dr. Cynthia Lee - UCSD . -. Spring 2011. . Theory of Computation Peer Instruction Lecture Slides by . Dr. Cynthia Lee, UCSD.  are licensed under a . Creative Commons Attribution-. An interactive PowerPoint presentation. Maddie Zeller . First period. Instructions . . 1. Read the question. . 2. Click on the answer. 3. Don’t click on anything else or it will go to the wrong slide. Prof. Shachar Lovett. Today’s Topics:. Knights and Knaves, and Proof by Contradiction. 2. 1. Knights and Knaves. 3. Knights and Knaves. Knights and Knaves scenarios are somewhat fanciful ways of formulating logic problems.