interface InterAA;

interface InterBB
{
	routine TestBB( aa : InterAA );
	routine Show();
}
interface InterAA
{
	routine TestAA( bb : InterBB );
	routine Show();
}

class One
{
	routine TestAA( bb : InterBB ){ bb.Show() }
	routine Show(){ io.writeln( "One::Show()" ) }
}

class Another
{
	routine TestBB( aa : InterAA ){ aa.Show() }
	routine Show(){ io.writeln( "Another::Show()" ) }
}

var o = One();
var a = Another();
o.TestAA( a );
a.TestBB( o );