interface IFoo inherits IFooBar
	var x as int

interface IBar inherits IFoo  # .error. Cyclical inheritance for "IBar" with ancestor types IFoo, IFooBar and back to IBar.
	var y as int

interface IFooBar inherits IFoo, IBar  # .error. Cyclical inheritance for "IFooBar" with ancestor types IFoo and back to IFooBar.
	pass