gf-3.1.6: examples/tutorial/food/Food.gf
abstract Food = {
cat
Phrase ; Item ; Kind ; Quality ;
flags startcat = Phrase ;
fun
Is : Item -> Quality -> Phrase ;
This, That : Kind -> Item ;
QKind : Quality -> Kind -> Kind ;
Wine, Cheese, Fish : Kind ;
Very : Quality -> Quality ;
Fresh, Warm, Italian, Expensive, Delicious, Boring : Quality ;
}