13. The computer-readable non-transitory storage medium of claim 12 , wherein determining the hypothetical context comprises: applying the mapping function to a current context; and producing the hypothetical context as an output of the mapping function.
13. The computer-readable non-transitory storage medium of claim 12 , wherein determining the hypothetical context comprises: applying the mapping function to a current context; and producing the hypothetical context as an output of the mapping function. 14. The computer-readable non-transitory storage medium of claim 13 , wherein the construction of the mapping function is also based on a mapping relationship between the historical contexts and corresponding prior hypothetical contexts.