class C<alpha,beta> {
    pub. alpha a;
	pub. beta b;
}

class B<beta2> {
    pub. A<alpha2:-beta2> a;
}

class A<alpha2> {
    pub. B<beta2:-alpha2> b;
    pub. alpha2 e;
}

main {
    var A<alpha2:-Int> x, B<beta2:-Int> y, C<alpha:-Int, beta:-C<alpha:-Txt, beta:-Txt>> z;
    x.b.a := x;
    x := y.a.b.a;
    x.b := y;
    z.b.b := z.b.a;
    z.b.a := "z";
    z.a := x.e;
    end x,y,z;
}