Correct the 2nd of this function's two examples. The value of =IPMT(5%/12;10;360;100000;0;1) should be -410.375128 + epsilon. The offset note and todo note for this function can then be removed.

We should also add a section at the beginning of the financial functions to set out some of the nomenclature for describing these functions. We should then use these terms consistently. For example, we could say:

An annuity is a recurring series of payments. A "simple annuity" is one where equal payments are made at equal intervals, and the compounding of interest occurs at those same intervals. The time between payments is called the "payment interval". Where payments are made at the end of the payment interval, it is called an "ordinary annuity". Where payments are made at the beginning of the payment interval, it is called an "annuity due". Periods are numbered starting at 1.

Corrected test case result to -410.375128 ± epsilon and removed Note and Todo.

Added to 5.12.1 General:
An annuity is a recurring series of payments. A "simple annuity" is one where equal payments are made at equal intervals, and the compounding of interest occurs at those same intervals. The time between payments is called the "payment interval". Where payments are made at the end of the payment interval, it is called an "ordinary annuity". Where payments are made at the beginning of the payment interval, it is called an "annuity due". Periods are numbered starting at 1.