Section 9.10

Section 9.10 - DeM, 3 5. ~G simp, 4 6. ~G ~~G 5,2, Conj...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Section 9.10 1. If an argument is sound, then the conclusion is necessarily true 2. If an argument is sound, then the negation of the conclusion is necessarily false Indirect proof- to show p is true, start off with ~p 1. A v (B•C) therefore C 2. A C 3. ~ C IP 4. ~A 2, 3, MT 5. B • C DS 1, 4 6. C • B Comm, 5 7. C 6, Simp 8 C • ~C Conj 7, 3 9. 1. (G v H) ~ G 2. ~~G IP 3. ~(G v H) 1,2, MT 4. ~G • ~H
Background image of page 1

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

View Full DocumentRight Arrow Icon
Background image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: DeM, 3 5. ~G simp, 4 6. ~G ~~G 5,2, Conj always start with invalidity 9.10 Section A exercises Try to demonstrate invalidity If theres one interpretation which demonstrates the arguments invalidity, then stop If no such interpretation, then you have to demonstrate its validity by constructing a proof S T (T S) UT v (~T ~U) (U v V) v (S v T) ~U (WX) (V...
View Full Document

This note was uploaded on 03/16/2011 for the course PHIL 045 taught by Professor Hopper during the Fall '07 term at GWU.

Page1 / 2

Section 9.10 - DeM, 3 5. ~G simp, 4 6. ~G ~~G 5,2, Conj...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online