Prolation Prolation Prolation is a term used in the theory of the mensural notation of medieval and Renaissance music to describe its rhythmic structure on a small scale, as opposed to "tempus", which described a larger scale. The term "prolation" is derived from the Latin "prolatio", first used by Philippe de Vitry in describing Ars Nova, a musical style that came about in 14th-century France. Prolation, together with tempus, corresponds roughly to the concept of time signature in modern music. Prolation describes whether a semibreve (whole note) is equal in length to two minims (half notes) ("minor prolation" or "imperfect prolation";
Time value of money is to emphasize that "u" is a "parameter" (fixed in any instance—the time when the cash flow will occur), while "t" is a "variable" (time). In other words, future cash flows are exponentially discounted (exp) by the sum (integral, formula_44) of the future discount rates (formula_45 for future, "r"("v") for discount rates), while past cash flows are worth 0 (formula_46), because they have already occurred. Note that the value "at" the moment of a cash flow is not well-defined – there is a discontinuity at that point, and one can use a convention (assume cash flows have already occurred, or