"""Create fact_checker
Generated by Phi-Octopus Eden
2025-11-07 10:58:31.954085
"""

```python
from typing import List, Dict


class FactChecker:
    """
    A class to check the validity of statements based on a predefined database.
    
    Attributes:
        knowledge_base: A dictionary where keys are statements and values indicate their truth value (True or False).
        
    Methods:
        __init__: Initializes the fact checker with an empty knowledge base.
        add_statement: Adds a statement to the knowledge base.
        check_fact: Checks if a given statement is true based on the knowledge base.
        update_knowledge_base: Updates the knowledge base with new statements.
    """
    
    def __init__(self):
        self.knowledge_base: Dict[str, bool] = {}
        
    def add_statement(self, statement: str, truth_value: bool) -> None:
        """Add a statement to the knowledge base."""
        if statement not in self.knowledge_base:
            self.knowledge_base[statement] = truth_value
        else:
            print(f"Statement '{statement}' already exists.")
            
    def check_fact(self, statement: str) -> bool:
        """Check if a given statement is true based on the knowledge base."""
        return self.knowledge_base.get(statement, False)
    
    def update_knowledge_base(self, new_statements: Dict[str, bool]) -> None:
        """Update the knowledge base with new statements."""
        for statement, truth_value in new_statements.items():
            if statement not in self.knowledge_base:
                self.knowledge_base[statement] = truth_value
            else:
                print(f"Statement '{statement}' already exists.")
                
    def __str__(self):
        return f"FactChecker with {len(self.knowledge_base)} statements."


# Example usage
if __name__ == "__main__":
    fact_checker = FactChecker()
    
    # Adding some predefined facts to the knowledge base
    fact_checker.add_statement("The Earth is round", True)
    fact_checker.add_statement("2 + 2 equals 4", True)
    
    # Checking a few facts
    print(f"Is 'The Earth is flat'? {fact_checker.check_fact('The Earth is flat')}")
    print(f"Is '2 + 2 equals 5'? {fact_checker.check_fact('2 + 2 equals 5')}")
    
    # Updating the knowledge base with new statements
    fact_checker.update_knowledge_base({
        "Pluto is a planet": False,
        "AI can learn and adapt": True
    })
    
    print(fact_checker)
```