Function reduced_kambe 

pub(super) fn reduced_kambe(
    twice_n: i32,
    value: Complex,
    w: Complex,
    sheet: Option<Sheet>,
) -> (Complex, f64)

F_n(v, w^2) of integer n (the odd Kambe orders of 1D spherical sums) from Kambe integrals, with a first-order bound on its absolute rounding error in units of epsilon.

Branch

The Kambe series takes the principal ln a of its argument a (= v up to rounding). Where the sheet of v (split_sheet) differs by delta, the result gains -delta x^-n J_n(x) w^2n with x^2 = -2 v w^2 (DLMF 8.2.10 in each term). That term is an entire function of v and w^2, so the jets of the continued F_n stay exact.