What do we mean by full case and parallel case?

àA full case is a case statement in which all possible all possible case expression can be matched with case items or case default.

à If it is possible to find binary expression that doesn't case item the case statement is not full.

àA parallel case statement is a case statement in which it is possible to match a case expression with one and only one case item if it is possible to find a case expression that would match more than one case item the matching case is called overlapping or non parallel.