equation icon  ^ ' 1-( p' (1) p' (1) ) -1- p' (1) q <Tab(x,x )> = 6 g bG ;p'a + g aG ;p'b - 12g q G ;p' gab 1 ( ' ' ) 1 [( ' ) ] - --- gpa gqb G(1);p'q'+ G(1);ab + --- G(1);p'p + G(1);pp gab 12 ( ) 12 1-- (1) 1- + 12G Rab - 2 R gab . (56)