C:\test>p1
use threads;;
{ 
    package t1; 
    sub new{ bless [], $_[ 0 ] }; 
    sub method{ print __PACKAGE__ . ": @_" } 
};;
{ 
    package t2; 
    our @ISA = 't1'; 
    sub method2{ print __PACKAGE__ . ": @_" } 
};;

$o = t2->new;;
print $o;;
t2=ARRAY(0x22b00c)

$o->method2( 1 .. 5 );;
t2: t2=ARRAY(0x22b00c) 1 2 3 4 5

$o->method( 1 .. 5 );;
t1: t2=ARRAY(0x22b00c) 1 2 3 4 5

print \&t2::method;;
CODE(0x22afac)

##</code><code>##

\&t2::method->( 1 .. 5 );;
[Undefined subroutine &t2::method called at (eval 13) line 1

##</code><code>##

$o->method( 1 .. 5 );;
[Undefined subroutine &t2::method called at (eval 14) line 1