((∀X)(∃Y)p(X,Y)) ⇔ ((∃X)(∀Y)q(X,Y))
- teorie + hypoteza dokazat pomoci tableaux, 20b
- najit vsechny neisomorfni dvouprvkove modely, 30b
∗ je funkce, ~ je relace
(one ∗ apple) ~ one
(one ∗ one) ~ apple
¬(one ~ apple)
(∀X)(X ~ X)
~~DISCUSSION~~