Let x0 of type ι be given.
Apply recip_SNo_poscase with
x0,
λ x1 x2 . SNoLt 0 x2 leaving 2 subgoals.
The subproof is completed by applying H1.
Apply recip_SNo_pos_pos with
x0 leaving 2 subgoals.
The subproof is completed by applying H0.
The subproof is completed by applying H1.