src/main/java/com/basistech/tclre/Dfa.java
int lastcold() {
        int nopr = 0;

        for (StateSet ss : stateSets.values()) {
            if (ss.noprogress && nopr < ss.getLastSeen()) {
                nopr = ss.getLastSeen();
            }
        }
        return nopr;
    }
int lastcold() {
        int nopr = 0;

        for (StateSet ss : stateSets.values()) {
            if (ss.noprogress && nopr < ss.getLastSeen()) {
                nopr = ss.getLastSeen();
            }
        }
        return nopr;
    }
lastcold - determine last point at which no progress had been made

@return offset or -1