typedef F<X> = void Function<Y extends X>();
F<X> toF<X>(X x) => null;
typedef Fcov<X> = X Function();
typedef Fcon<X> = Function(X);
typedef Finv<X> = X Function(X);

class Acov<X extends Fcov<Y>, Y> {}

class Acon<X extends Fcon<Y>, Y> {}

class Ainv<X extends Finv<Y>, Y> {}

typedef FcovBound<X extends num> = X Function();
typedef FconBound<X extends num> = Function(X);
typedef FinvBound<X extends num> = X Function(X);

class AcovBound<X extends FcovBound<Y>, Y extends num> {}

class AconBound<X extends FconBound<Y>, Y extends num> {}

class AinvBound<X extends FinvBound<Y>, Y extends num> {}

class A<X> {}

typedef FcovCyclicBound<X extends A<X>> = X Function();
typedef FconCyclicBound<X extends A<X>> = Function(X);
typedef FinvCyclicBound<X extends A<X>> = X Function(X);

class AcovCyclicBound<X extends FcovCyclicBound<Y>, Y extends A<Y>> {}

class AconCyclicBound<X extends FconCyclicBound<Y>, Y extends A<Y>> {}

class AinvCyclicBound<X extends FinvCyclicBound<Y>, Y extends A<Y>> {}

typedef FcovCyclicCoBound<X extends Function(X)> = X Function();
typedef FconCyclicCoBound<X extends Function(X)> = Function(X);
typedef FinvCyclicCoBound<X extends Function(X)> = X Function(X);

class AcovCyclicCoBound<X extends FcovCyclicCoBound<Y>, Y extends Function(Y)> {
}

class AconCyclicCoBound<X extends FconCyclicCoBound<Y>, Y extends Function(Y)> {
}

class AinvCyclicCoBound<X extends FinvCyclicCoBound<Y>, Y extends Function(Y)> {
}

class B<X> {}

void testTypeAliasAsTypeArgument() {}
void testNested() {}
main() {}