∀ a b c, ((a - b) - c) = ((a - c) - b)

Theorem minus_minus_comm : forall (a:nat), forall (b:nat), forall (c:nat), logic.eq (nat) (minus (minus a b) c) (minus (minus a c) b).

theorem minus_minus_comm : \forall (a:nat). \forall (b:nat). \forall (c:nat). (eq) (nat) ((minus) ((minus) a b) c) ((minus) ((minus) a c) b).

theorem minus_minus_comm : forall (a:nat.nat) , forall (b:nat.nat) , forall (c:nat.nat) , (((logic.eq_) (nat.nat)) ((((nat.minus) ) ((((nat.minus) ) (a)) (b))) (c))) ((((nat.minus) ) ((((nat.minus) ) (a)) (c))) (b)).

minus_minus_comm : LEMMA (FORALL(a:nat_sttfa.sttfa_nat):(FORALL(b:nat_sttfa.sttfa_nat):(FORALL(c:nat_sttfa.sttfa_nat):logic_sttfa_th.eq[nat_sttfa.sttfa_nat](nat_sttfa.minus(nat_sttfa.minus(a)(b))(c))(nat_sttfa.minus(nat_sttfa.minus(a)(c))(b)))))

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