"""Create fact_checker
Generated by Phi-Octopus Eden
2025-11-05 20:56:54.941348
"""

```python
from typing import List, Union

class FactChecker:
    """
    A simple fact-checking tool that evaluates the truthfulness of statements based on a predefined set of facts.
    """

    def __init__(self, facts: List[str]):
        self.facts = {fact.strip().lower() for fact in facts}

    def check_fact(self, statement: str) -> Union[bool, str]:
        """
        Checks if the given statement is true based on the predefined facts.

        :param statement: The statement to be checked.
        :return: True if the statement is a fact, False otherwise. If the statement cannot be determined,
                 returns "Cannot determine" as it might contain variables or complex logic not handled here.
        """
        statement = statement.lower().strip()
        for fact in self.facts:
            # Simple keyword-based matching
            if fact in statement:
                return True
        return False

# Example usage
if __name__ == "__main__":
    facts = ["The Earth is round", "Water boils at 100 degrees Celsius"]
    checker = FactChecker(facts)

    print(checker.check_fact("Is the Earth spherical?"))  # Should return True
    print(checker.check_fact("Does water boil at 80 degrees Celsius?"))  # Should return False
    print(checker.check_fact("What is the temperature of boiling water?"))  # Should return "Cannot determine"
```

This code defines a `FactChecker` class that can check simple statements against predefined facts. The `check_fact` method uses keyword matching to determine if the statement aligns with any known fact. For more complex logic, it returns a message indicating inability to determine truthfulness.