Since subroutines return lists, and arrays are flattened in list context, your arrays are probably being flattened into a single list. What you probably want is to return 2 array references, so the 2 arrays remain distinct 'objects' e.g

sub foo {
  my @x = 1 .. 5;
  my @y = reverse 1 .. 5;
  return \@x, \@y;
}

my($ar1, $ar2) = foo();

print "array 1 - @$ar1\n";
print "array 2 - @$ar2\n";

__output__

array 1 - 1 2 3 4 5
array 2 - 5 4 3 2 1
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See. the likes of tye's References quick reference and japhy's "list" is a four letter word for more info on references and contexts.
HTH

_________
broquaint