String span = mention.substring(0,idx);
String type = mention.substring(idx+1);
String[] locs = P_COLON.split(span);
IntIntPair fst = getTokenBasedMentionAux(trees, locs[0], true);
IntIntPair snd = getTokenBasedMentionAux(trees, locs[1], false);
if (fst == null || snd == null || fst.i2 > snd.i2)
{
System.err.println("WRONG");
return null;