ABSTRACT
A s a n o th e r i l lu s t r a t io n I d educe , once m o re , in c x q t j th e fo rm u la s ( a l 4) , ( a ! 5 ) , b u t th is t im e m a k in g use o f (Q D ):
b y (aOO) b y M P [re le v a n t fo r Vx v b y ( R l ) , x e ig e n v a r ia b le , b y (Q D ), x re le v a n t b y (Q D) [ fo r Vx ( v - * w )
b y (aOO) a n d M P b y M P (a O l) an d M P , no e ig e n - b y (QD) [v a r ia b le s b y ( R 0 1 ) , x e ig e n v a r ia b le ,
r e le v a n t fo r V x ( v - * w ) b y (QD)
T h e c o m p a r it io n w i t h th e e a r lie r d e d u c tio n s show s t h a t , as in th e p ro p o s i t io n a l case, th e e m p lo y m e n t o f (QD) a v o id s th e use o f v a r io u s p ro p o s it io n a l ta u to lo g ie s w h ic h , s o m e tim e s , m a y h a v e a p p e a re d a r t i f ic ia l . O n th e o th e r h a n d , i t re q u ire s th e c a re fu l b o o k k e e p in g o f e ig e n v a r ia b le s .
