Let x be given.
Assume Hx.
We prove the intermediate claim Lx: SNo x.
An
exact proof term for the current goal is
real_SNo x Hx.
Apply SNoLt_trichotomy_or_impred x 0 Lx SNo_0 to the current goal.
rewrite the current goal using recip_SNo_negcase x Lx H1 (from left to right).
We will
prove - recip_SNo_pos (- x) ∈ real.
We will
prove recip_SNo_pos (- x) ∈ real.
Apply minus_SNo_Lt_contra2 x 0 Lx SNo_0 to the current goal.
rewrite the current goal using minus_SNo_0 (from left to right).
An exact proof term for the current goal is H1.
Assume H1: x = 0.
rewrite the current goal using H1 (from left to right).
rewrite the current goal using recip_SNo_0 (from left to right).
An
exact proof term for the current goal is
real_0.
rewrite the current goal using recip_SNo_poscase x H1 (from left to right).
∎