"""Create reasoning_engine
Generated by Phi-Octopus Eden
2025-11-06 13:12:48.015757
"""

```python
from typing import List, Optional


class KnowledgeBase:
    def __init__(self):
        self.knowledge = []

    def add_fact(self, fact: str) -> None:
        """Add a fact to the knowledge base."""
        self.knowledge.append(fact)

    def get_facts(self) -> List[str]:
        """Retrieve all facts in the knowledge base."""
        return self.knowledge


class RuleBase:
    rules = {
        'A': ['B', 'C'],
        'B': [],
        'C': ['D'],
        'D': []
    }

    @staticmethod
    def apply_rules(facts: List[str]) -> Optional[str]:
        """Apply predefined rules to the given facts and return a new fact if possible."""
        for fact in facts:
            if fact in RuleBase.rules:
                for conclusion in RuleBase.rules[fact]:
                    if all(fact in base.get_facts() for fact in RuleBase.rules[fact]):
                        return conclusion
        return None


class ReasoningEngine:
    def __init__(self, knowledge_base: KnowledgeBase):
        self.knowledge_base = knowledge_base

    def infer_new_fact(self) -> Optional[str]:
        """
        Infer a new fact from existing facts using predefined rules.
        
        :return: The inferred fact or None if no inference can be made
        """
        return RuleBase.apply_rules(self.knowledge_base.get_facts())

    def update_knowledge_base(self, new_facts: List[str]) -> None:
        """Update the knowledge base with new facts."""
        for fact in new_facts:
            self.knowledge_base.add_fact(fact)


# Example usage
if __name__ == "__main__":
    kb = KnowledgeBase()
    engine = ReasoningEngine(kb)
    
    # Add initial facts to the knowledge base
    kb.add_fact('A')
    print(engine.infer_new_fact())  # Should return 'B' or 'C'

    kb.add_fact('B')  # Adding B, which is a conclusion of A
    new_fact = engine.infer_new_fact()
    if new_fact:
        print(f"Inferred new fact: {new_fact}")
    
    # Try to infer a new fact with more facts added
    kb.add_fact('C')
    new_fact = engine.infer_new_fact()
    if new_fact:
        print(f"Inferred new fact: {new_fact}")

    # Update knowledge base with inferred facts
    engine.update_knowledge_base([new_fact])
```