before-after

Before/after verification is a technique for proving that a stage actually changed system behavior. Instead of just checking that the final state is valid, you capture what was true BEFORE implementation and what should be true AFTER implementation. The pair proves your stage caused the change.

This matters because without before/after thinking, you can't distinguish:

A delta-proof is verification that proves a state transition occurred.

生成织机计划之前/之后的验证对。通过捕获实现前后的状态来证明阶段实际上改变了系统行为。用于增量验证——通过比较系统状态来证明新命令、端点、模块或错误修复是否有效。 来源：cosmix/claude-loom。