this predicate returns true if the program is runing in fastforward mode, e.g., as in the initial phase of a ::antescofoantescofo::starfrom... command.

The fastforward mode is used to reach a location in the score where the normal execution resumes. In fastforward mode, all computation are done, except the final sending of messages, which is inhibited. The time also is spent in virtual time, meaningthat the clock goes as fast as possible. This predicate can be used to avoid or to perform a specific computation in this mode.

See also @is_fastforward, @is_following_on, @is_paused, @is_playing_on, @is_running, and @is_stopped.