entity("Person")
	.hasOne("name", { is: Text })
	.hasOne("age", { is: Number })
	.is("mother").ofMany("children", { are: "people" })
	.is("owner").ofMany("cars")
	.is("creator").ofMany("created_cars", { are: "cars" });

entity("Car")
	.hasOne("engine")
	.hasOne("creator", { is: "person" });

entity("Engine")
	.belongsTo("car");