Core Concepts

This guide explains the fundamental concepts behind Modality.

The Five Pillars

Concept	Purpose
Append-only log	Immutable, ordered history
State machines	Finite, verifiable behaviors
Modal logic	Express temporal constraints
Predicates	Bind identity to logic
Potentialism	Safe accumulation of rules

How They Fit Together

1. A contract is an append-only log of signed commits
2. Commits can add state, rules, or perform actions
3. A model (labeled transition system) defines what actions are possible
4. Rules (temporal formulas) constrain which evolutions are valid
5. Predicates bind real-world identity (signatures) to logical constraints
6. Potentialism ensures rules can only shrink the space of valid futures

Dive into each concept:

• Append-Only Logs
• State Machines
• Modal Logic
• Predicates
• Potentialism