class A : b by a { companion object {} } class A : b by a + b() * 5 { companion object {} } class A : b by (a) { companion object {} } class A : b by (a {}) { companion object {} } class A : b by a[a {}] { companion object {} } class A : b by a(a {}) { companion object {} } class A : b by object { fun f() = a {} } { companion object {} }