Rules for Passage of Time
delta(<TO:Timer | on:true:T, time:T>, T’)
<TO:Timer | on:true’, time:T+T’>
delta(<N:TimedNode | clock:T, timerSet:S>, T’)
<N:TimedNode | clock:T+T’, timerSet:delta(S)>
sys( ... tNode ... lNode ... iNode )
sys( ... delta(tNode,T) ... lNode ... iNode )