Comment by mw888

A clear hierarchy may be secured through these constraints. That's the unifier - it'd be hard to achieve these three without it.

A one-pager begs of you to find the foundational value simply - no fooling yourself with a multitude of prospects and complexity.

The separable aspect makes explicit the need to build the foundation to stand on its own. You can't lean on the branches prematurely as if features are solid ground.

The single-defining constraint forces one to conceive and recognize the single-most fundamental functionality - and its shape, and its abilities; its character.