Assume that your client has a AAA credit rating from Standard and Poors. They wish to sell variable rate debt securities maturing in 2031 bearing interest at a rate of the US treasury security rate for obligations of a comparable maturity plus 50 basis points, with the interest rate to be reset annually. They also wish to retain the right to redeem those securities (for example, to eliminate restrictive debt covenants) at any time after January 1, 2016. Your job is to draft a redemption pricing clause that establishes that price upon redemption that would fully protect and compensate any holder of said securities for the value of their securities (basically, to enable them to reinvest the redemption proceeds for the same return). Think about how to do this in terms of the treasury yield curve (and net present value), bearing in mind that this has to be a legally enforceable contract term not longer than perhaps 1"-2" of text on a printed page.