... argument of type e, we obtain the interval of e of type inter. (λx. beginning•x): e→inst (λx. ending•x): e→inst Applying these functions to any argument x of type e, we obtain the beginning/ending ... inter→inst (λx. end•x):inter→inst Applying this function to any argument x of type inter, we obtain the beginning/ending instant of x of type inst. By definition, beg•[A,B] = A and end•[A,B] = ... April 5th 2003: instant [2003,4,5,3,0] An extended interval is a set of consecutive instants determined by a beginning instant and an ending instant. (ex) on April 5th, 2003: interval ...