CaseExpression = (((C,A,S,E), { [SP], CaseAlternatives }-) | ((C,A,S,E), [SP], Expression, { [SP], CaseAlternatives }-)), [[SP], (E,L,S,E), [SP], Expression], [SP], (E,N,D) ;
CaseAlternatives = (W,H,E,N), [SP], Expression, [SP], (T,H,E,N), [SP], Expression ;