gf-3.2: book/examples/chapter2/Food.gf
abstract Food = {
flags startcat = Comment ;
cat
Comment ; Item ; Kind ; Quality ;
fun
Pred : Item -> Quality -> Comment ;
This, That : Kind -> Item ;
Mod : Quality -> Kind -> Kind ;
Wine, Cheese, Fish : Kind ;
Very : Quality -> Quality ;
Fresh, Warm, Italian,
Expensive, Delicious, Boring : Quality ;
}