for (Node pre : getPrePNSet(t)) {
            Interval end2 = ((Time) pre).getEndTime();
            if (!end2.equals(start)) {
                result.add("Concurrently inconsistency: start" + nodeStr(t) + timeStr(start.toString()) + " != finish"
                        + nodeStr(pre) + timeStr(end2.toString()) + ".");