principle-subtract-before-you-add

先减后加

When evolving a system, remove complexity first, then build.

演化系统时，先去掉复杂度，再建设。

Why: Adding to a complex system compounds complexity. Removing first leaves less code, reveals the essential structure, and usually makes the next design obvious. Default to subtraction.

为什么： 往复杂系统上加东西会复合复杂度。先减留下更少代码、露出本质结构，通常下一步设计也就清楚了。默认做减法。

Make simplification a continual investment. Leave the design slightly simpler and more capable behind the same or smaller surface than you found it.

把简化当成持续投入。离开时，设计应比你接手时略更简单、能力更强，公开面相同或更小。

The pattern:

模式：

• Sequence removal before construction

• Cut before you polish (get to the minimum before investing in quality)

• Design for observed usage, not speculative edge cases

• No speculative validators, parsers, or guards beyond what the spec demands

• Simplify prompts (remove redundant instructions, excessive templates)

• When a reference has no novel content, delete it rather than leaving a stub

• 删除排在建设前面

• 先砍再抛光（到最小再投资质量）

• 为观察到的用法设计，不为臆测边界情况

• 不做规格之外的臆测校验器、解析器或守卫

• 简化 prompt（去掉冗余指示、过量模板）

• 引用没有新内容就删，别留空壳