// @dart = 2.9
class A<X> {}

class C<X, Y extends A<X>> {}

class D<X extends num, Y extends A<X>> {}

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

class F<X extends num, Y extends X Function()> {}

main() {}
var lc = <C>[];
var ld = <D>[];
var le = <E>[];
var lf = <F>[];
var mc = <C, C>{};
var md = <D, D>{};
var me = <E, E>{};
var mf = <F, F>{};