fact: Definition negative_apart_zero (z : R) (Nz : z < 0) : z ≶ 0 := pseudo_order_lt_apart z 0 Nz.
imports: HoTT.Classes.interfaces.abstract_algebra HoTT.Classes.interfaces.orders HoTT.Classes.theory.groups HoTT.Classes.theory.rings HoTT.Classes.orders.semirings