Delay until an interval of length (at least) D seconds has passed,
or the task is aborted to at least the current ATC nesting level.
This is an abort completion point.
The body of this procedure must perform all the processing
required for an abortion point.
Delay until Clock has reached (at least) time T,
or the task is aborted to at least the current ATC nesting level.
The body of this procedure must perform all the processing
required for an abortion point.