feature f1 {
    sub c_t by c t;
    sub f_i by f i;
    sub f_f_i by f f i;
} f1;


# Even if it has exactly the same content as feature f1,
# the lookup should not be shared.
feature f2 {
    sub c_t by c t;
    sub f_i by f i;
    sub f_f_i by f f i;
} f2;

feature f3 {
    sub [f_i f_l f_f_i f_f_l] by f [i l f_i f_l];
} f3;

feature f4 {
    sub [f_i f_l f_f_i f_f_l] by [f f f_f f_f] [i l i l];
} f4;

@class = [f_i f_l];
lookup l1 {
   sub @class by f [i l];
} l1;

feature f5 {
   sub @class' lookup l1 [i l];
} f5;

feature f6 {
    sub [f_i f_i]' j by [f f] [i i];
} f6;