Replace the current semantics section with this: ---------------------------------------------- Semantics: Compute the internal rate of return for a series of cash flows. The result of IRR is the rate at which the NPV() function will return zero with the given Values. There is no closed form for IRR. Implementations typically return an approximate solution using an iterative method, in which case the Guess parameter may be used to initialize the iteration. If the implementation is unable to converge on a solution given a particular Guess, it may return an error.