I am reviewing code which has the following at the top of the script:

#!/tool/bin/perl
use strict;
use warnings;
[download]

Then inside each subroutine it includes the same:

sub sub1
{
    use strict;
    use warnings;
    ...
}

sub sub2
{
    use strict;
    use warnings;
    ...
}

sub subN
{
    use strict;
    use warnings;
    ...
}
[download]

Is there any purpose to this seemingly redundant use of "use strict" and "use warnings" or can these statements be removed from each individual subroutine if I keep them at the top of the script?