Let x0 of type ι be given.
Let x1 of type ι be given.
Apply mul_SNo_pos_neg with
x0,
recip_SNo x1 leaving 4 subgoals.
The subproof is completed by applying H0.
Apply SNo_recip_SNo with
x1.
The subproof is completed by applying H1.
The subproof is completed by applying H2.
Apply recip_SNo_of_neg_is_neg with
x1 leaving 2 subgoals.
The subproof is completed by applying H1.
The subproof is completed by applying H3.