equation icon  Hab (x, x') = V ab (x,x'), (378) g'd' g'd' G ab (x, x') = 1U ab (x,x')d(s) - 1V ab (x,x')h(s), (379) S g'd' 2 g'd' 2 g'd' ab 1 ab ab [ 1 ] GR g'd'(x, x') = -U g'd'(x,x')[d+(s)- d-(s)] + V g'd'(x,x') h+(- s) + -h(s) . (380) 2 2