In addition to the four old program units: PROGRAM (that is the main program), SUBROUTINE, FUNCTION and BLOCK DATA , the new concept MODULE has been added, as well as some new things in the old units. ... POSITIVE NUMBERS ASSUMED TYPE(INTERVAL), INTENT(IN) :: A, B TYPE (INTERVAL) :: INTERVAL_MULTIPLICATION INTERVAL_MULTIPLICATION%LOWER = A%LOWER * B%LOWER INTERVAL_MULTIPLICATION%UPPER = A%UPPER * B%UPPER END FUNCTION INTERVAL_MULTIPLICATION FUNCTION INTERVAL_DIVISION(A, B) ! ...

... UNIX and Linux don't incorporate the user interface into the kernel; instead, they let it be implemented by user level programs. ... This arrangement makes the system more flexible, but has the disadvantage that it is simple to implement a different user interface for each program, making the system harder to learn. ... X also does not implement a user interface; it only implements a window system, i.e., tools with which a graphical user interface can be implemented. ... Sun May 4 14:08:43 EEST 1997...