public static bool Eval(string a, Teacher aVal, string b, Teacher bVal) { var aClass = DomainUtils.DecodeClass(a); var bClass = DomainUtils.DecodeClass(b); var aDay = DomainUtils.DecodeDay(a); var bDay = DomainUtils.DecodeDay(b); var aHour = int.Parse(DomainUtils.DecodeHour(a)); var bHour = int.Parse(DomainUtils.DecodeHour(b)); if (aClass == bClass && aDay == bDay && (aHour - 1 == bHour || aHour + 1 == bHour)) { return(aVal != bVal); } return(true); }