experiment: N0_bridge_histogram
kind: gen_lineage
seed: 20260704
n_replicates: 60
generations: 200

# Bridge / harness-faithfulness check (Layer 1.5 build-order Stage B): run the E2 grounding
# phase-boundary sweep through the NEURAL runner with the histogram model, which is exactly
# neutral Wright-Fisher drift with immigration. Stationary H must track the closed form
# H_eq = H* * m(2n+m-1)/(n+2nm+m^2) and reproduce a critical g* << 1 — i.e. the neural
# plumbing reproduces the analytic core before any real network is trained. R=1 so every
# grounding policy reduces to the proportional immigration model H_eq is derived for.
synthetic:
  K: 200
  R: 1
  tail: zipf
  zipf_s: 1.1
  tail_frac: 0.5
  tail_threshold: 1.0e-3
  init: truth
  style_len: 2
  style_vocab: 4
  id_base: 2

model:
  kind: histogram

dynamics:
  n: 200
  grounding: {m: 0, policy: proportional}   # m is overwritten per g by the sweep
  remint: {enabled: false, period: null, H_gate: null}

metrics:
  kl_floor: 1.0e-9
  support_eps: 1.0e-9

sweep:
  - param: g
    values: [0.0, 0.005, 0.01, 0.02, 0.05, 0.1, 0.2, 0.4]

output:
  dir: results/N0