Apply H1 to the current goal.
Assume _ H.
Apply H to the current goal.
Let k be given.
Assume H.
Apply H to the current goal.
Assume H.
Apply H to the current goal.
Let m be given.
Assume H.
Apply H to the current goal.
Assume H.
Apply H to the current goal.
Assume H.
Apply H to the current goal.
We prove the intermediate
claim Lk:
k ∈ n.
rewrite the current goal using Hkm (from right to left).
An exact proof term for the current goal is H1m.
Apply IHn k Lk H1k to the current goal.
Let p be given.
Assume H.
Apply H to the current goal.
We use p to witness the existential quantifier.
Apply andI to the current goal.
An exact proof term for the current goal is Hp.
rewrite the current goal using Hkm (from right to left).
An exact proof term for the current goal is Hk.
An exact proof term for the current goal is Hm.
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