The constant term is

ΣΣ cλ, μ .
aλμ

Let aν be a value of x which makes the fraction infinite. The residue of

ΣΣΣ cλ, μ+ Σ γλ
(aμ - aνex)λaλν eλx

is equal to the residue of

ΣΣΣ cλ, μ,
(aμ - aνex)λ

and when ν = μ, the residue vanishes, so that we have to consider

ΣΣ cλ, μ,
aλν (1 - ex)λ

and the residue of this is, by the first lemma,