Equation Icon  { --------------} G (s,λ,ζ,ζ-) = 1- G (s + iλ,ζ, ζ) + G (s + iλ,ζ,ζ) , (3.22 ) R 2 -- i{ -- --------------} GI (s,λ,ζ,ζ ) = − 2 G(s + iλ,ζ,ζ) − G (s + iλ, ζ,ζ) . (3.23 )