Function py_hindmarsh_rose_simulate 

pub(crate) fn py_hindmarsh_rose_simulate<'py>(
    py: Python<'py>,
    x0: f64,
    y0: f64,
    z0: f64,
    b: f64,
    r: f64,
    s: f64,
    x_rest: f64,
    dt: f64,
    x_threshold: f64,
    n_steps: usize,
    current: f64,
) -> (Bound<'py, PyArray1<f64>>, i64, f64, f64, f64)

Parity contract with sc_neurocore.neurons.models.hindmarsh_rose.HindmarshRoseNeuron.simulate: for the same parameters and constant input the returned x trace, upward- crossing spike count, and final (x, y, z) state are bit-identical to the Python RK4 reference (the right-hand side is exact arithmetic — x.powi(3) = x*x*x, x.powi(2) = x*x, no transcendental functions — so even the chaotic bursting trace reproduces exactly).