GoKawiil
Tech News
Following Claude Code creator Boris Cherny's comment that the Opus model used TLA+ to detect race conditions, online discussion has surged around formal verification as a fix for agentic software bugs. A longtime TLA+ educator and advocate argues this enthusiasm is overblown, noting that formal verification only checks properties that engineers explicitly define, and many important properties can't even be expressed in TLA+.
An interactive tutorial walks through TLA+, a formal specification language used to describe transition systems and verify their properties. It illustrates core concepts like states, actions, safety and liveness properties using a leader-election example among three computers, showing how a model checker can explore all possible states and surface counterexamples when rules are violated.
A blog post examines Bend 2, a programming language designed for an AI-assisted workflow where humans write 'laws' and AI writes implementations plus formal proofs that a compiler checks. Using Bend's own homepage demo as an example, the author notes that stating a simple game rule takes 58 lines of code, while the AI-generated proof of that rule balloons to 442 lines. The piece argues this ratio illustrates a broader vibe-coding pitfall rather than being unique to Bend.