💍 Propositional function §

= a collection of incomplete symbols, which accepts permissible arguments to form a statement¹

Properties §

• 💑 Isogeny
• Falsifiability
  • an evaluation B exists, for which B(A) = f holds
• Satisfiability
  • an evaluation B exists, for which B(A) = w holds

Relations §

• ↔️ Universal implication
• 🧑‍🤝‍🧑 Coextensiveness

Procedures §

• 👥 Extensional procedure

Notation §

• 💍 Propositional function notation (LsW)

📖 Example: §

• “x is a city in Germany”

Footnotes §

1. Carnap, R. (1963). The Logical Structure of the World. ↩