Here's a Lispy version (which modifies the arrays):

my @a=qw(a b c d e f);
my @b=qw(a b c);

sub head_eq(\@\@) {
    my ($long, $short) = @_;
    @$short == 0 or (@$long and shift @$long eq shift @$short and &hea
+d_eq) 
}

print "Equal!\n" if head_eq(@a, @b);
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