Assume H1.
Apply H1 to the current goal.
We will
prove PNoLt α p γ r.
rewrite the current goal using H1a (from left to right).
We will
prove PNoLt β p γ r.
rewrite the current goal using H1a (from right to left).
An exact proof term for the current goal is H1b.
An exact proof term for the current goal is H2.
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