"""Create reasoning_engine
Generated by Phi-Octopus Eden
2025-11-08 18:31:01.566113
"""

```python
from typing import List


class ReasoningEngine:
    """
    A basic reasoning engine for solving limited reasoning problems.
    This implementation uses a simple rule-based approach to address constraints.

    Example Usage:
    >>> engine = ReasoningEngine()
    >>> result = engine.reason([(1, 2), (3, 4)], "add")
    >>> print(result)
    [3, 7]
    """

    def __init__(self):
        pass

    def reason(self, inputs: List[tuple], operation: str) -> List[int]:
        """
        Perform a basic reasoning step on given inputs based on the specified operation.

        :param inputs: A list of tuples representing data pairs.
        :param operation: String specifying an arithmetic or logical operation to perform.
                          Supported operations are 'add', 'subtract', 'multiply'.
        :return: A list of results after applying the operation to each pair in the input list.
        """
        if not all(isinstance(pair, tuple) and len(pair) == 2 for pair in inputs):
            raise ValueError("All inputs must be pairs (tuples with two elements).")

        result = []
        operations = {
            'add': lambda x, y: x + y,
            'subtract': lambda x, y: x - y,
            'multiply': lambda x, y: x * y
        }

        if operation not in operations:
            raise ValueError(f"Unsupported operation '{operation}'. Supported operations are: {', '.join(operations.keys())}")

        for pair in inputs:
            result.append(operations[operation](*pair))

        return result


# Example usage
if __name__ == "__main__":
    engine = ReasoningEngine()
    example_inputs = [(1, 2), (3, 4)]
    operation = "add"
    results = engine.reason(example_inputs, operation)
    print(results)  # Expected output: [3, 7]
```