# 3. PTERI Model & Universal Trust Layer

- [3.1 The Core Mental Model](/3.-pteri-model-and-universal-trust-layer/3.1-the-core-mental-model.md)
- [3.2 Universal Trust Layer](/3.-pteri-model-and-universal-trust-layer/3.2-universal-trust-layer.md)
- [3.3 What PTERI Is NOT](/3.-pteri-model-and-universal-trust-layer/3.3-what-pteri-is-not.md)