∀ n, O ≤ n

Theorem le_O_n : forall (n:nat), le O n.

theorem le_O_n : \forall (n:nat). (le) (O) n.

theorem le_O_n : forall (n:nat.nat) , (((nat.le_) ) ((nat.O) )) (n).

le_O_n : LEMMA (FORALL(n:nat_sttfa.sttfa_nat):nat_sttfa.le(nat_sttfa.sttfa_O)(n))

Printing for OpenTheory is not working at the moment.