abstract class Foo { public virtual signal void foo () { } public abstract void baz (); public virtual void manam () { } } class Bar : Foo { public override void foo () { assert (base.foo != null); } public override void baz () { assert (base.baz != null); } public override void manam () { assert (base.manam != null); } } void main () { var bar = new Bar (); bar.foo (); bar.baz (); bar.manam (); }