Return true if a specified set of operations has completed.

Arguments:

AcquireTargets operations

The set of operations to check on.

Example:

In the following example the telescope is told to track Jupiter, then the schedule is told to wait until the telescope has slewed to Jupiter and acquired it, before starting observing it for 10 minutes.

 track jupiter
 until $acquired(source)
 until $elapsed > 0:10:0