↩ 🔵 🔵 🔵 ❪✺₀❫ Portals ○ Systems Theory 𓆩⚪𓆪 ❪✺❫ Network Concepts ○ ❪✺₁❫ System Classes ○ ❪✺₂❫ System Domains ○ Feedback ○ Scalability ○ State ○