Rename Fock-Attention to 'Fock Attention (MLP V_theta)', fix stale pre-causal-leak-fix 9.30 PPL comparisons, add V_theta-vs-exchange-mechanism insight

README.md

@@ -361,7 +361,7 @@ model.eval()
 |---|---|---|---|---|
 | Matched Attention (baseline) | **7.81** | 19.5M | -- | No |
 | [Hybrid SPLM+Attn](https://huggingface.co/dimitarpg13/semsimula-hybrid-splm) | **8.50** | ~19.0M | +0.69 | No |
-| [Fock Attention](https://huggingface.co/dimitarpg13/semsimula-fock-attention) | **9.42** | 16.7M | +1.61 | No |
+| [Fock Attention (MLP V_theta)](https://huggingface.co/dimitarpg13/semsimula-fock-attention) | **9.42** | 16.7M | +1.61 | No |
 | **Fock-PARFLM v2.1** (this model, `prefix_causal_registers=True`) | **9.70** | 17.4M | +1.89 | **No — fixed and verified** |
 | [Multi-Xi PARFLM](https://huggingface.co/dimitarpg13/semsimula-parflm-multixi) | **12.06** | 17.6M | +4.25 | No |
 | [Multi-Xi SPLM](https://huggingface.co/dimitarpg13/semsimula-splm-multixi) | **11.51** | 16.5M | +3.70 | No |
@@ -370,6 +370,8 @@ model.eval()
 
 Fock-PARFLM v2.1 remains a competitive attention-free model, 1.89 PPL behind matched attention while offering \\(O(1)\\) inference memory (vs. attention's \\(O(T)\\)) and the Fock mechanism's register-based state. Fock Attention (direct exchange, no registers) is now the best-performing attention-free model in the family on this benchmark.
 
+**Note on what actually separates this model from the family-best 9.04 PPL:** both this model and [Fock Attention (MLP V_theta)](https://huggingface.co/dimitarpg13/semsimula-fock-attention) use the same plain MLP \\(V_\theta\\); the [depth-conditioned anisotropic-Gaussian sibling](https://huggingface.co/dimitarpg13/semsimula-fock-parflm-anisogaussian-vtheta) keeps this model's register-based Fock mechanism unchanged and only swaps \\(V_\theta\\)'s shape, yet reaches 9.04 PPL. Swapping the exchange mechanism instead (registers here vs. direct exchange in Fock Attention), with \\(V_\theta\\) held at MLP, only moves PPL by \\(\approx\\)0.3 points. On TinyStories, \\(V_\theta\\)'s shape appears to be the dominant lever, not the choice of Fock/exchange mechanism — see that sibling's [Why the Anisotropic Correction Wins](https://huggingface.co/dimitarpg13/semsimula-fock-parflm-anisogaussian-vtheta#why-the-anisotropic-correction-wins) section for the full ablation table.
+
 ## SPLM Family Overview
 
 This model is part of the **Semantic Simulation SPLM family**:
@@ -385,7 +387,7 @@ This model is part of the **Semantic Simulation SPLM family**:
 | Fock-PARFLM v2.1 (depth-cond. isotropic Gaussian) | Bounded multi-context + pairwise + Fock | TinyStories | 16.33 | [semsimula-fock-parflm-depthcond-vtheta](https://huggingface.co/dimitarpg13/semsimula-fock-parflm-depthcond-vtheta) |
 | Fock-PARFLM v2.1 (depth-cond. anisotropic Gaussian + fock-reg) | Bounded, ellipsoidal multi-context + pairwise + Fock | TinyStories | 9.04 | [semsimula-fock-parflm-anisogaussian-vtheta](https://huggingface.co/dimitarpg13/semsimula-fock-parflm-anisogaussian-vtheta) |
 | Fock-PARFLM v2.1 (aniso-Gaussian + fock-reg, first-order/Fock-G1) | Same as above, gradient-flow integrator | TinyStories | 8.95 | [semsimula-fock-parflm-anisogaussian-vtheta-fock-g1](https://huggingface.co/dimitarpg13/semsimula-fock-parflm-anisogaussian-vtheta-fock-g1) |
-| Fock-Attention | Fock + attention | TinyStories | 9.42 | [semsimula-fock-attention](https://huggingface.co/dimitarpg13/semsimula-fock-attention) |
+| Fock Attention (MLP V_theta) | Fock + attention | TinyStories | 9.42 | [semsimula-fock-attention](https://huggingface.co/dimitarpg13/semsimula-fock-attention) |
 | Hybrid SPLM+Attn | Attention + SPLM refinement | TinyStories | 8.50 | [semsimula-hybrid-splm](https://huggingface.co/dimitarpg13/semsimula-hybrid-splm) |
 | Fock-PARFLM v2.1 (aniso-Gaussian + fock-reg, gamma sweep, d=384) | Bounded, ellipsoidal multi-context + pairwise + Fock — 8-way gamma sweep + geodesic analysis | OpenWebText | 278.27 (best of 8, 3K-step sweep) | [semsimula-fock-parflm-anisogaussian-vtheta-owt-d384-gammasweep](https://huggingface.co/dimitarpg13/semsimula-fock-parflm-anisogaussian-vtheta-owt-d384-gammasweep) |
 | Fock-PARFLM v2.1 (aniso-Gaussian + fock-reg, gamma sweep, d=768) | Bounded, ellipsoidal multi-context + pairwise + Fock — 8-way gamma sweep + geodesic analysis | OpenWebText | 326.97 (best of 8, 3K-step sweep) | [semsimula-fock-parflm-anisogaussian-vtheta-owt-d768-gammasweep](https://huggingface.co/dimitarpg13/semsimula-fock-parflm-anisogaussian-vtheta-owt-d768-gammasweep) |