Background to problem with nested data structures

Thanks Jeff for the quick response. For some reasons I memorized the following pattern:

$list = @(            
    (1,2)            
    (3,4)            
)            
$list.count            
             

which flattens the structure and yields 4 instaed of the correct syntax

$list = (            
(1,2),            
(3,4)            
)            
$list.count            
            

which yields 2

Once using the wrong pattern there is no escape without help.