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": "reverse_words", "description": "Reverses the order of words in a sentence.", "parameters": {"sentence": {"description": "The input sentence.", "type": "str"}}}, {"name": "find_max_subarray_sum", "description": "Finds the maximum sum of a contiguous subarray within a list of integers.", "parameters": {"nums": {"description": "The input list of integers.", "type": "List[int]"}}}, {"name": "flatten_list", "description": "Flattens a nested list into a single-level list.", "parameters": {"nested_list": {"description": "The nested list to be flattened.", "type": "List"}}}, {"name": "split_list", "description": "Splits a list into chunks of a specified size.", "parameters": {"lst": {"description": "The input list.", "type": "List"}, "chunk_size": {"description": "The size of each chunk.", "type": "int"}}}]
Reverse the words in 'Programming is challenging' and flatten the nested list [1, [2, [3, [4, [5, [6, [7, [8, [9]]]]]]]]].
user
assistant
[{"name": "reverse_words", "arguments": {"sentence": "Programming is challenging"}}, {"name": "flatten_list", "arguments": {"nested_list": [1, [2, [3, [4, [5, [6, [7, [8, [9]]]]]]]]]}}]