Whole note (or "breve", hence the British name "semibreve") lasts twice as long as a whole note. A related symbol is the whole rest (or semibreve rest). It usually applies for an "entire measure", but may occasionally mean a rest for the duration of a whole note, in longer time signatures such as or . (An entire measure rest is drawn centered within the measure, whereas a rest lasting for a whole note is aligned to where the note would be.) Whole rests are drawn as filled-in rectangles generally hanging under the second line from the top of a musical staff, though
Time value of money not already occurred), or simply not define the value at that point. In case the discount rate is constant, formula_47 this simplifies to where formula_49 is "time remaining until cash flow". Thus for a stream of cash flows "f"("u") ending by time "T" (which can be set to formula_50 for no time horizon) the value at time "t," formula_51 is given by combining the values of these individual cash flows: This formalizes time value of money to future values of cash flows with varying discount rates, and is the basis of many formulas in financial mathematics, such as the Black–Scholes