Let t be given.
We prove the intermediate
claim HtR:
t ∈ R.
We prove the intermediate
claim Htprop:
¬ (Rlt t 0) ∧ ¬ (Rlt 1 t).
An
exact proof term for the current goal is
(SepE2 R (λx0 : set ⇒ ¬ (Rlt x0 0) ∧ ¬ (Rlt 1 x0)) t HtI).
We prove the intermediate
claim Hnlt_t0:
¬ (Rlt t 0).
An
exact proof term for the current goal is
(andEL (¬ (Rlt t 0)) (¬ (Rlt 1 t)) Htprop).
We prove the intermediate
claim Hnlt_1t:
¬ (Rlt 1 t).
An
exact proof term for the current goal is
(andER (¬ (Rlt t 0)) (¬ (Rlt 1 t)) Htprop).
We prove the intermediate
claim HtS:
SNo t.
An
exact proof term for the current goal is
(real_SNo t HtR).
An exact proof term for the current goal is HltS.
We prove the intermediate
claim H1ltt:
1 < t.
rewrite the current goal using
(minus_SNo_invol t HtS) (from right to left).
An exact proof term for the current goal is H1ltmm.
We prove the intermediate
claim H1lt:
Rlt 1 t.
An
exact proof term for the current goal is
(RltI 1 t real_1 HtR H1ltt).
An exact proof term for the current goal is (Hnlt_1t H1lt).
An exact proof term for the current goal is HltS.
We prove the intermediate
claim H0ltmt:
0 < (minus_SNo t).
We prove the intermediate
claim Htltm0:
t < minus_SNo 0.
We prove the intermediate
claim Htlt0S:
t < 0.
rewrite the current goal using
minus_SNo_0 (from right to left).
An exact proof term for the current goal is Htltm0.
We prove the intermediate
claim Htlt0:
Rlt t 0.
An
exact proof term for the current goal is
(RltI t 0 HtR real_0 Htlt0S).
An exact proof term for the current goal is (Hnlt_t0 Htlt0).
∎