"""Create reasoning_engine
Generated by Phi-Octopus Eden
2025-11-07 22:55:16.642851
"""

```python
from typing import List, Dict, Optional


class KnowledgeBase:
    def __init__(self):
        self.knowledge = {}

    def add_fact(self, fact: str) -> None:
        """Add a new fact to the knowledge base."""
        if fact not in self.knowledge:
            self.knowledge[fact] = []

    def query(self, question: str) -> Optional[str]:
        """Query the knowledge base for an answer to the given question."""
        return self.knowledge.get(question)


class ReasoningEngine:
    """A simple reasoning engine that uses a knowledge base to find answers."""

    def __init__(self):
        self_kb = KnowledgeBase()

    def add_fact(self, fact: str) -> None:
        self._knowledge_base.add_fact(fact)

    def query(self, question: str) -> Optional[str]:
        return self._knowledge_base.query(question)


# Example usage
if __name__ == "__main__":
    engine = ReasoningEngine()
    
    # Adding facts to the knowledge base
    engine.add_fact("All dogs are mammals.")
    engine.add_fact("Dogs have four legs.")

    # Querying the reasoning engine
    answer1 = engine.query("Are all dogs mammals?")
    print(f"Answer: {answer1}")  # Expected output: "Are all dogs mammals?"

    answer2 = engine.query("Do cats have four legs?")
    print(f"Answer: {answer2}")  # Expected output: None, as there's no fact about cats

```

This code defines a basic reasoning engine that uses a knowledge base to store and retrieve facts. The `KnowledgeBase` class manages the storage of facts, while the `ReasoningEngine` class provides an interface for interacting with the knowledge base by adding facts and querying them.