Update README: add training as primary use case

README.md

@@ -4,17 +4,40 @@ tags:
   - theorem-proving
   - formal-methods
   - lean4
-  - physics
-  - science
+task_categories:
+  - text-generation
+  - feature-extraction
+language:
+  - en
 size_categories:
   - 1K<n<10K
 ---
 
 # Lean4-PhysLean
 
-Formalization of physics in Lean 4.
+Structured dataset from **PhysLean** — Formalization of physics.
+
+**7,026 declarations** extracted from Lean 4 source files.
+
+## Applications
+
+- Training language models on formal proofs
+- Fine-tuning theorem provers
+- Retrieval-augmented generation for proof assistants
+- Learning proof embeddings and representations
 
 ## Source
 
 - **Repository:** https://github.com/HEPLean/PhysLean
-- **License:** Apache-2.0
+
+## Schema
+
+| Column | Type | Description |
+|--------|------|-------------|
+| fact | string | Declaration body |
+| type | string | theorem, def, lemma, etc. |
+| library | string | Source module |
+| imports | list | Required imports |
+| filename | string | Source file path |
+| symbolic_name | string | Identifier |
+| docstring | string | Documentation (if present) |