Three Structural Limits

TWO-LAYER HIERARCHY

CONTEXTX_t

SYSTEM 1Latent Policyπ_latent

Zₜ

SYSTEM 0Whole-Body TrackerD_tracker

ACTIONA_t

THREE STRUCTURAL LIMITS

INTERFACEInsufficient motion interface

Z_t = π_latent(X_t)

Compression can discard task-relevant control information before action is determined.

TRAININGSeparate training, coupled inference

θ₁ ← L_latentθ₀ ← L_track

The modules learn from separate objectives, then form one execution chain at deployment.

EXECUTIONLow-level action boundary

A_t ∈ Reach(D_tracker)

A frozen tracker can execute only actions inside its learned control distribution.