pressurised(p1).  pressurised(p2) <- on(t1) & pressurised(p1).
pressurised(hws) <- on(t2) & pressurised(p2).  pressurised(p3) <-
on(t1) & pressurised(p1).  pressurised(p4) <- pressurised(hws).
pressurised(p5) <- pressurised(hws).  flow(shower) <- on(t2) &
pressurised(p2).  flow(shower) <- on(t5) & pressurised(p5).  wet(sink)
<- on(t3) & pressurised(p3).  wet(sink) <- on(t6) & pressurised(p4).
flow(d3) <- wet(sink) & unplugged(sink).  wet(bath) <- flow(shower).
flow(d2) <- wet(bath) & unplugged(bath).  flow(d1) <- flow(d2).
flow(d1) <- flow(d3).  wet(floor) <- wet(sink) & plugged(sink).
wet(floor) <- wet(bath) & plugged(bath).  on(t1).  on(t2).  off(t3).
off(t4).  off(t5).  on(t6).  unplugged(bath).  plugged(sink).