begin
  string (255) s, a, b

  s = "A string with xxx in the middle"

  s -> a.("xxx").b

  newline

  if s -> a.("xxx").b start
    newline
  finish

  s -> ("xxx").b

  newline

  if s -> ("xxx").b start
    newline
  finish

  s -> a.("xxx")

  newline

  if s -> a.("xxx") start
    newline
  finish

endofprogram