Let x, y and i be given.
We prove the intermediate
claim Hlub:
R_lub A l.
We prove the intermediate
claim Hcore:
l ∈ R ∧ ∀a : set, a ∈ A → a ∈ R → Rle a l.
An
exact proof term for the current goal is
(andEL (l ∈ R ∧ ∀a : set, a ∈ A → a ∈ R → Rle a l) (∀u : set, u ∈ R → (∀a : set, a ∈ A → a ∈ R → Rle a u) → Rle l u) Hlub).
We prove the intermediate
claim Hub:
∀a : set, a ∈ A → a ∈ R → Rle a l.
An
exact proof term for the current goal is
(andER (l ∈ R) (∀a : set, a ∈ A → a ∈ R → Rle a l) Hcore).
We prove the intermediate
claim HaA:
a ∈ A.
We prove the intermediate
claim HxiR:
apply_fun x i ∈ R.
We prove the intermediate
claim HyiR:
apply_fun y i ∈ R.
We prove the intermediate
claim HsuccO:
ordsucc i ∈ ω.
An
exact proof term for the current goal is
(omega_ordsucc i HiO).
We prove the intermediate
claim HaR:
a ∈ R.
An exact proof term for the current goal is (Hub a HaA HaR).
∎