You are a function calling AI model. You are provided with function signatures within <tools></tools> XML tags. You may call one or more functions to assist with the user query. Don't make assumptions about what values to plug into functions.
system
[{"name": "find_next_greater_element", "description": "Finds the next greater element for each element in a list.", "parameters": {"nums": {"description": "The list of numbers.", "type": "List[int]"}}}, {"name": "expand_around_center", "description": "Helper function to expand around a center for finding palindromic substrings.", "parameters": {"s": {"description": "The input string.", "type": "str"}, "left": {"description": "The left index of the center.", "type": "int"}, "right": {"description": "The right index of the center.", "type": "int"}}}, {"name": "compound_interest", "description": "Calculates the compound interest of an investment.", "parameters": {"principal": {"description": "The initial investment amount.", "type": "float", "default": 1}, "rate": {"description": "The annual interest rate expressed as a decimal.", "type": "float", "default": 1}, "time": {"description": "The time in years for which the investment is held.", "type": "float"}, "n": {"description": "The number of times interest is compounded per year. Defaults to 1.", "type": "int, optional"}}}, {"name": "is_valid_sudoku", "description": "Checks if a 9x9 Sudoku board is valid.", "parameters": {"board": {"description": "The Sudoku board represented as a 2D list of strings.", "type": "List[List[str]]"}}}, {"name": "note_duration", "description": "Calculates the duration between two musical notes based on their frequencies and the tempo.", "parameters": {"freq1": {"description": "The frequency of the first note in Hz.", "type": "int", "default": 120}, "freq2": {"description": "The frequency of the second note in Hz.", "type": "int", "default": 120}, "bpm": {"description": "The tempo of the music in beats per minute. Defaults to 120.", "type": "int, optional"}}}, {"name": "is_valid_palindrome", "description": "Checks if a string is a valid palindrome, considering only alphanumeric characters and ignoring case.", "parameters": {"s": {"description": "The input string.", "type": "str"}}}]
Calculate the duration between a note at 440 Hz and another at 880 Hz at a tempo of 120 BPM.
user
assistant
[{"name": "note_duration", "arguments": {"freq1": 440, "freq2": 880, "bpm": 120}}]