sub is_included {
  my ($a,$b)=@_;
#  while ($a) {              # UPDATED since buggy
   while (length $a) {
    my $c=substr($a,0,1);
    return 0 if  
      $a =~ s/$c//g  >  $b =~ s/$c//g ;
  }
  return 1;
}
    
print is_included(qw/ababa babababab/);         # 1
print is_included(qw/babababab ababa/);         # 0
print is_included(qw/EASYPEASY PEARLYGATES/);   # 0