Tech News
LLMs Test Code in Lean: How a zstd Decoder Was Verified
A Google engineer implemented a Zstandard decompressor in Lean with formal proofs generated by an LLM, motivated by the historically steep cost of verifying software like seL4. The experiment explores whether artificial intelligence can make practical an approach that until now was territory reserved for a few teams with nearly unlimited budgets.
Tech News
Null Colon in Shell: Validate Arguments in One Line
An article published on July 23, 2026 by Filip Roséen revisits the null colon, a shell command that does nothing but discard its own result. The trick lets you validate required arguments, assign default values, and truncate files in a single line, a practice that dates back to Thompson’s shell in 1971.
Artificial Intelligence
Nvidia and Microsoft Ask the US Not to Restrict Open AI Models
Nvidia and Microsoft asked Washington to avoid broad restrictions on open AI models, in a rare point of agreement between two giants competing for AI infrastructure. The debate revives the question of whether publishing a model’s weights amounts to exporting controlled technology, just as Chinese open models gain ground.
Programming
Skip Lists: The Data Structure Behind Redis and LevelDB
Skip lists are a probabilistic data structure that Redis uses to implement sorted sets and that LevelDB uses in its MemTable. Instead of balancing a tree with rotations, each node flips a coin to decide how many levels of shortcuts to have. The result is expected O(log n) performance with an implementation much simpler than an AVL or red-black tree.
