"""Create reasoning_engine
Generated by Phi-Octopus Eden
2025-11-08 03:41:11.800742
"""

```python
class ReasoningEngine:
    """
    A simple reasoning engine that can evaluate conditions based on given facts.
    
    This engine supports basic logical operations such as AND, OR, NOT to combine and evaluate conditions.

    Args:
        facts (dict): A dictionary of facts where the keys are variable names and values are boolean states.
        
    Methods:
        add_fact(fact: str, value: bool) -> None:
            Adds or updates a fact in the engine's knowledge base.
            
        remove_fact(fact: str) -> None:
            Removes a fact from the engine's knowledge base if it exists.

        evaluate(condition: str) -> bool:
            Evaluates a logical condition based on current facts and returns True or False.
    """

    def __init__(self):
        self.facts = {}

    def add_fact(self, fact: str, value: bool) -> None:
        """
        Adds or updates a fact in the engine's knowledge base.

        Args:
            fact (str): The name of the fact to be added or updated.
            value (bool): The boolean state of the fact.
        """
        self.facts[fact] = value

    def remove_fact(self, fact: str) -> None:
        """
        Removes a fact from the engine's knowledge base if it exists.

        Args:
            fact (str): The name of the fact to be removed.
        """
        if fact in self.facts:
            del self.facts[fact]

    def evaluate(self, condition: str) -> bool:
        """
        Evaluates a logical condition based on current facts and returns True or False.

        Args:
            condition (str): A logical condition string that may contain variables as keys from the facts dictionary.
        
        Returns:
            bool: The result of evaluating the condition.
        """
        def eval_condition(expression):
            return eval(expression, self.facts)
        
        try:
            return eval_condition(condition)
        except KeyError as e:
            print(f"Fact '{e}' not found in knowledge base.")
            return False
        except Exception as e:
            print(f"An error occurred: {e}")
            return False


# Example Usage:

if __name__ == "__main__":
    engine = ReasoningEngine()
    
    # Add some facts
    engine.add_fact("rainy", True)
    engine.add_fact("cold", False)

    # Evaluate a condition
    print(engine.evaluate("rainy and not cold"))  # Should return True

    # Remove a fact
    engine.remove_fact("rainy")

    # Try to evaluate the same condition again, should return an error message
    result = engine.evaluate("rainy or cold")
    if not result:
        print(f"Evaluation result: {result}")
```

This code defines a `ReasoningEngine` class that can add facts and evaluate logical conditions. The example usage demonstrates adding facts, evaluating a condition, removing a fact, and attempting to re-evaluate the same condition after removal.