package T1;
sub s1 {print("T1:s1\n")}

package T2;
use base T1;

package T3;
use base T2;
sub s1 {shift->SUPER::s1}

package main;
no strict 'refs';
exists($T2::{s1}) && die('not here');
T3->s1;
exists($T2::{s1}) && die('here');