@result = map { $^a + $^b } 1,2,3,4;
  # 3,7

  @result = map -> $a, $b { $a + $^b } 1,2,3,4;
  # 3,7

  # And:
  $result = reduce { $^a + $^b * $^c } 1,2,3,4,5;
  # same as
  $result = (1 + 2 * 3) + 4 * 5;
  # i.e.
  # 27