lean-content-preservation

What problem does it solve?

This Skill provides structured patterns and lemmas for rigorously proving that functions operating on byte arrays (like compression or decompression algorithms) correctly preserve existing data and accurately produce new data.

Core Features & Use Cases

• Prefix Preservation Proofs: Demonstrate that a function does not alter the initial bytes of an input buffer.
• Content Characterization: Prove what new bytes a function generates, whether as raw slices, repeated values (RLE), or element-wise mappings.
• Compositional Proofs: Combine proofs for sequential operations, handling complex workflows like multi-block decompression.
• Use Case: When developing a new compression algorithm in Lean 4, use these patterns to formally verify that your decompression function correctly reconstructs the original data without corruption.

Quick Start

Use the lean-content-preservation skill to prove that the copyBytes function preserves the prefix of the destination byte array.