∀ n, n = (n + O)

Theorem plus_n_O : forall (n:nat), logic.eq (nat) n (plus n O).

theorem plus_n_O : \forall (n:nat). (eq) (nat) n ((plus) n (O) ).

theorem plus_n_O : forall (n:nat.nat) , (((logic.eq_) (nat.nat)) (n)) ((((nat.plus) ) (n)) ((nat.O) )).

plus_n_O : LEMMA (FORALL(n:nat_sttfa.sttfa_nat):logic_sttfa_th.eq[nat_sttfa.sttfa_nat](n)(nat_sttfa.plus(n)(nat_sttfa.sttfa_O)))

Printing for OpenTheory is not working at the moment.