UniversalLanguage(languageA)
∀x ∀y (∃z (¬(x=y) ∧ Know(x, z) ∧ Know(y, z) ∧ UniversalLanguage(z)) → CanCommunicateWith(x, y) ∧ CanCommunicateWith(y, x))
¬CanCommunicateWith(katya, danil)
Know(katya, languageA)
Know(danil, languageA)