Solutions12

# Solutions12 - Chapter 12 Hints and Selected Solutions...

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

Chapter 12: Hints and Selected Solutions Section 12.3 (page 327) 12.1 The argument is valid and the proof is a good one. In the following, we repeat the proof, but being explicit about the proof methods being used. x [( Brillig ( x ) Tove ( x )) ( Mimsy ( x ) Gyre ( x ))] y [( Slithy ( y ) Mimsy ( y )) Tove ( y )] xSlithy ( x ) x [ Slithy ( x ) Mimsy ( x )] Proof: By the third premise, we know that something in the domain of discourse is slithy. In order to use Elim , let b be one of these slithy things. By the second premise, everything that is either slithy or mimsy is tove. Hence, by Elim , Intro and Elim , we know that b is a tove. By the ﬁrst premise, using the same methods, we see that b is mimsy and gyre. Hence b is mimsy, using Elim . Thus, b is both slithy and mimsy, using Intro . Hence, something is both slithy and mimsy, by Intro . 12.4 The argument is valid. We give an informal proof. y

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.

## This note was uploaded on 03/25/2009 for the course LOGIC 20034 taught by Professor Dhoe during the Spring '09 term at Hanover.

### Page1 / 4

Solutions12 - Chapter 12 Hints and Selected Solutions...

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

View Full Document
Ask a homework question - tutors are online