@{$difference[0]}

##</code><code>##

Error -- >Can't use string ("ARRAY(0x2c992e0)") as an ARRAY ref while "strict refs" in use at 

##</code><code>##

@{$difference}

##</code><code>##

Global symbol "$difference" requires explicit package name at 
Global symbol "$intersect" requires explicit package name at 
Global symbol "$union" requires explicit package name at .

##</code><code>##

@difference

##</code><code>##

DEBUG: - difference links values ARRAY(0x32690e0) ARRAY(0x3269090) ARRAY(0x322d040) ARRAY(0x3276990) ARRAY(0x322d060) ARRAY(0x3269f80) ARRAY(0x3269040)
DEBUG: - intersect links values
DEBUG: - union links values ARRAY(0x32690e0) ARRAY(0x3269090) ARRAY(0x322d040) ARRAY(0x3276990) ARRAY(0x322d060) ARRAY(0x3269f80) ARRAY(0x3269040)