lc: lc uc: uc uc_first: uc_first date = date date1 = 2003-09-05 date2 = 2003/09/05 date3 = 20030905 date4 = 20030905 first = first second = second first_name = first_name first or second = or first and second = and first eq second = equal first_name like regex = like if first then first else second = if if second then first else second = if