Exercise 6.3 - Answers

 

1

 (i)

$x[Fbx®"y[GbyÙ¬b=a]]

$x[Fax®"y[GbyÙ¬b=b]]

$x[Fbx®"y[GbyÙ¬b=b]]
 
(ii)

$x[Fax®"y[GayÙ¬b=a]]

$x[Fax®"y[GbyÙ¬a=a]]

$x[Fax®"y[GayÙ¬a=a]]

2

 (i)

4          ¬b=c (from lines 2 and 1 by the left hand rule)

4          b=a (from lines 2 and 3 by the left hand rule)

4          ¬a=a (from lines 3 and 1 by the left hand rule): the tableau closes.

4          ¬c=c (from lines 3 and 1 by the right hand rule): the tableau closes.

4          c=b (from lines 3 and 2 by the right hand rule)

Close Window