Modus (medieval music) "tempus" (corresponding to the modern concept of a measure or bar and referring to the division of "breves" into two or three "semibreves") and "prolatio" (the division of "semibreves" into two or three "minims"). The "modus longarum" was applied primarily to pieces based on a cantus firmus tenor part in long note values. An even longer temporal unit was the "modus maximarum", but it is of little practical importance outside of the 13th century . Modus (medieval music) In medieval music theory, the Latin term modus (meaning "a measure", "standard of measurement", "quantity", "size", "length", or, rendered in English, mode)
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