say my $candidates = all
  «Alphabet subdermatoglyphic
  ‘Emily Jung Schwartzkopf’».pick: 2;

say “All isograms? {$_ ?? ‘✔’ !! ‘❌’}”
  given is-isogram($candidates).so;

sub is-isogram (Str $_ --> Bool) {
  .uc.comb(/<:L>/).Bag ⊆ 'A'..'Z';
}