SALE versus the complete TD7 system

The source links For SALE to arXiv:2306.02451 and NeurIPS 2023. SALE is a state–action representation mechanism; TD7 combines it with TD3, checkpoints, replay, and stability choices. Whole-system gains cannot all be attributed to the encoder.

Representation objective

Write zs=f(s)z_s=f(s) and zsa=g(zs,a)z_{sa}=g(z_s,a). A conceptual objective predicts the next-state embedding:

Lenc=E[∥g(f(s),a)−sg⁡(f(s′))∥2].\mathcal L_{enc}=\mathbb E\left[\|g(f(s),a)-\operatorname{sg}(f(s'))\|^2\right].

Actual normalization, stop-gradient, fixed/target representation versions, and schedules matter. Critics can retain original states and actions. Low-dimensional observations can still involve complex dynamics, but embedding prediction alone does not establish a homomorphism or optimal control.

Component Purpose Required comparison
Decoupled representation Keep value losses from arbitrarily reshaping the encoder End-to-end and encoder-free controls
Fixed embeddings/normalization Stabilize targets and scales Schedules and gradient boundaries
Replay/loss design including LAP Change sample use and weighting Separate from representation ablations
Policy checkpoints Select a training-time policy copy Assessment versus independent evaluation
Value clipping Limit selected extrapolated values Thresholds and underestimation
Offline BC term Restrict fixed-data policy drift Separate offline and online protocols

Evidence and scope

The long source describes online MuJoCo, offline D4RL, component ablations, and runtime. Its score tables refer to reported paper configurations; no PDF was uploaded or independently checked here, so they are not presented as new verification.

The central evidence concerns low-dimensional continuous control. Visual inputs, multitask VLAs, dynamic robots, and real deployment require further experiments. Account for compute relative to base TD3.

Related reading: checkpoint mechanisms, abstraction, and extrapolation.

Selected references from the source notes