# formal_model  

**Scope:** Minimal formal model.  
**Audience:** Reviewers and contributors.  
**Guarantees:** State and constraint sets are explicit.  
**Non-Goals:** Full proofs.  
Why: This doc exists to record its single responsibility for review.  

## Overview  
This doc defines a minimal formal model.  
Architecture context lives in [architecture/architecture.md](../architecture/architecture.md).  
Vocabulary aligns with [../concepts/core_concepts.md](../concepts/core_concepts.md).  

## Contracts  
State space S is the set of agent states.  
Action space A is the set of signals.  
Transition function T maps (S, A) to S.  
Constraint set C limits valid transitions.  
Constraints align with [architecture/invariants.md](../architecture/invariants.md).  
Validation uses [tests/unit/test_protein_system_rigidity.py](https://github.com/bijux/agentic-proteins/blob/main/tests/unit/test_protein_system_rigidity.py).  

## Invariants  
S, A, T, and C remain consistent.  
Definitions align with [../governance/core.md](../governance/core.md).  
Evidence aligns with [tests/unit/test_protein_system_rigidity.py](https://github.com/bijux/agentic-proteins/blob/main/tests/unit/test_protein_system_rigidity.py).  

## Failure Modes  
Ambiguous symbols break reviewability.  
Drift in definitions breaks [../governance/core.md](../governance/core.md).  
Unlinked references break [../meta/DOCS_STYLE.md](../meta/DOCS_STYLE.md).  

## Extension Points  
Model updates follow [../meta/DOCS_STYLE.md](../meta/DOCS_STYLE.md).  
Extensions align with [architecture/experimental.md](../architecture/experimental.md).  
Evidence updates align with [tests/unit/test_docs_contract.py](https://github.com/bijux/agentic-proteins/blob/main/tests/unit/test_docs_contract.py).  

## Exit Criteria  
This doc is obsolete when a formal spec exists.  
The replacement is [architecture/architecture.md](../architecture/architecture.md).  
Obsolete docs are removed.  

Code refs: [tests/unit/test_protein_system_rigidity.py](https://github.com/bijux/agentic-proteins/blob/main/tests/unit/test_protein_system_rigidity.py).  
