Let z be given.
Assume Hz.
We prove the intermediate claim Lp0z: F (proj0 z).
An
exact proof term for the current goal is
CD_proj0R z Hz.
We prove the intermediate claim Lp1z: F (proj1 z).
An
exact proof term for the current goal is
CD_proj1R z Hz.
We prove the intermediate
claim Lmp0z:
F (- proj0 z).
Apply F_minus to the current goal.
An exact proof term for the current goal is Lp0z.
We prove the intermediate
claim Lmp1z:
F (- proj1 z).
Apply F_minus to the current goal.
An exact proof term for the current goal is Lp1z.
We will
prove proj0 (pa (- proj0 z) (- proj1 z)) = - proj0 z.
An
exact proof term for the current goal is
CD_proj0_2 (- proj0 z) (- proj1 z) ?? ??.