* {} (prázdna množina)
* {a}
* {b}
* {c}
* {d}
* {a, b}
* {a, c}
* {a, d}
* {b, c}
* {b, d}
* {c, d}
* {a, b, c}
* {a, b, d}
* {a, c, d}
* {b, c, d}
* {a, b, c, d}