↩ 🔵 🔵 🔵 ❪𝛿❫ Quantities ○ Number ○꠹ ❪𝛿₁’❫ Integers ○ ❪𝛿₁❫ Physical Numbers ○ ❪𝛿₁ₐ❫ Constants ○ ❪֎₈❫ Values ○