class MathematicalNativeAGI:
    def __init__(self):
        self.knowledge_base = {}
        self.mathematical_functions = {
            'add': lambda x, y: x + y,
            'subtract': lambda x, y: x - y,
            'multiply': lambda x, y: x * y,
            'divide': lambda x, y: x / y if y != 0 else float('inf'),
            'square_root': lambda x: x ** 0.5 if x >= 0 else None,
            # Add more mathematical functions as needed
        }
    
    def learn(self, data):
        """Learn from new data and update knowledge base."""
        for key in data:
            self.knowledge_base[key] = data[key]
    
    def query(self, question):
        """Respond to a user's question based on the current knowledge base."""
        # Simple keyword matching
        if any(key in question for key in self.mathematical_functions.keys()):
            return self.execute(question)
        
        elif 'definition' in question:
            term = question.split('definition of ')[1]
            if term in self.knowledge_base:
                return self.knowledge_base[term]
            else:
                return "Definition not found."
        
        # More complex logic for different types of queries
        else:
            return "I'm sorry, I didn't understand your query."

    def execute(self, command):
        """Execute a mathematical operation based on the user's input."""
        tokens = command.split()
        if len(tokens) == 3 and tokens[1] in self.mathematical_functions:
            func = self.mathematical_functions[tokens[1]]
            try:
                x = float(tokens[0])
                y = float(tokens[2])
                return func(x, y)
            except ValueError:
                return "Invalid input. Please provide valid numbers."
        else:
            return "Invalid command. Please use a format like 'command number number'."

# Example usage
agi = MathematicalNativeAGI()
agi.learn({'pi': 3.14159, 'euler': 2.71828})
print(agi.query('What is the value of pi?'))  # Output: 3.14159

print(agi.execute('add 5 3'))  # Output: 8.0