sub letter_counts {
    my @letters = split//, lc(shift);
    my %counts;
    for(@letters){
        $counts{$_}++;
    }
    return %counts
}

my $word1 = 'bantha fodder';
my $word2 = 'banana slug';

my %counts1 = letter_counts($word1);
my %counts2 = letter_counts($word2);

my $result = 'are equivalent';

test_loop:
for(keys %counts1, keys %counts2){
    if(!defined $counts2{$_} || !defined $counts1{$_}){
        $result = 'are not equivalent';
        last test_loop
    }
}

print "'$word1' and '$word2' $result\n";