Apply Hpq1 to the current goal.
Let δ be given.
Assume Hpq2.
Apply Hpq2 to the current goal.
Assume Hd1 Hd2.
Assume Hpq3.
Apply Hpq3 to the current goal.
Assume Hpq3.
Apply Hpq3 to the current goal.
Assume Hpq5: q δ.
We will
prove PNoLt α p β r.
We use δ to witness the existential quantifier.
Apply andI to the current goal.
An exact proof term for the current goal is Hd.
Apply and3I to the current goal.
An exact proof term for the current goal is Hpq3.
An exact proof term for the current goal is Hqr.
An exact proof term for the current goal is Hpq4.
We will prove r δ.
An
exact proof term for the current goal is
iffEL (q δ) (r δ) (Hqr δ Hd2) Hpq5.