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 can be computed as that whose interest equals the annuity payment amount: Note that no money enters or leaves the combined system of endowment principal + accumulated annuity payments, and thus the future value of this system can be computed simply via the future value formula: Initially, before any payments, the present value of the system is just the endowment principal (formula_24). At the end, the future value is the endowment principal (which is the same) plus the future value of the total annuity payments (formula_25). Plugging this back into the equation: Without showing the formal derivation here, the perpetuity