enum Alphabet {
	A = 'A', B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z,
	a = 'a', b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z
};


forall( istype & | istream( istype ) | { istype & ?|?( istype &, E & ); } )
istype & ?|?( istype & is, E & e ) {
	choose ( e ) {
	  case A: is | label( A ); e = A;
	  case B: is | label( B ); e = B;
	  case C: is | label( C ); e = C;
	} // choose
	return is;
}

forall( ostype & | ostream( ostype ) | { ostype & ?|?( ostype &, E ); } )
	ostype & ?|?( ostype & os, E e ) {
	choose ( e ) {
	  case A: os | label( A );
	  case B: os | label( B );
	  case C: os | label( C );
	} // choose
	return os;
}

enum( char * ) Friends { Fred = "FRED", Mary = "MARY", Jane = "Jane" };

forall( istype & | istream( istype ) | { istype & ?|?( istype &, Friends & ); } )
istype & ?|?( istype & is, Friends & friend ) {
	choose ( friend ) {
	  case Fred: is | label( A ); friend = A;
	  case Mary: is | label( B ); friend = B;
	  case Jane: is | label( C ); friend = C;
	} // choose
	return is;
}

forall( ostype & | ostream( ostype ) | { ostype & ?|?( ostype &, Friends ); } )
	ostype & ?|?( ostype & os, Friends friend ) {
	choose ( friend ) {
	  case Fred: os | value( Fred );
	  case Mary: os | value( Mary );
	  case Jane: os | value( Jane );
	} // choose
	return os;
}


int main() {
	E e = A;
	sin | e;
	sout | e;
	Friends friend = Mary;
	sin | friend;
	sout | friend;
}