b(1-S.r)(1-Sr) =S.E(1-SI)+Sr(SE+S.EB) SE b, (-STX-SE)-5S 2-) s. 0-)080-sr-ss ( )( ) ( ) ( ) 21 11 21 11 12 2 2 22 11 1 1 1 S E S S S E S b b S S g g L L g = - G + G + G - G - G ( )( ) S L S g S S g L S E b - G - G - G G = 22 11 12 21 21 2 1 1 ( ) ( ) ( )( ) 2 11 22 12 21 2 2 21 2 2 2 2 1 1 1 2 1 1 2 1 g L g L L L L S S S S S E P b - G - G - G G = - G = - G