nx_f64_rootfind.nx

nx_f64_rootfind.nx -- GAMS-F: sovereign nonlinear root-finder (the nonlinear-solve capability class). Robust BISECTION on a sign-changing bracket [a,b] -- guaranteed convergence (1 bit/iter), no derivative needed. The function under test is selected by a function-id (the dialect has no function pointers); rf_eval composes our PROVEN kernels (exp / cos / polynomial), so the root-finder rests only on gated primitives. fid 0: x^2 - 2 (root sqrt2) fid 1: cos(x) - x (Dottie number) fid 2: exp(x) - 2 (root ln2) fid 3: x^3 - x - 2 (root ~1.5214) f64 software-IEEE throughout. (Brent superlinear convergence = the perf-exceed upgrade.) module: nishi-core.math.f64_rootfind depends: nishi-core.math.f64, nishi-core.math.f64_exp, nishi-core.math.f64_sincos capability: F64_ROOTFIND_BISECTION license_tier: ORIGINAL