We can use a timer to give a window of priority to one computation over another. In this example, we run expressions F and G concurrently. For one second, F has priority; F's result is published immediately, but G's result is held until the time interval has elapsed. If neither F nor G publishes a result within one second, then the first result from either is published.
val x = F val y = G Let( x | Rwait(1000) >> y )