{R : Type u} →
  [inst : Rack R] →
    {motive : (a a_1 : Rack.PreEnvelGroup R) → Rack.PreEnvelGroupRel' R a a_1 → Sort u_1} →
      {a a_1 : Rack.PreEnvelGroup R} → Rack.PreEnvelGroupRel' R a a_1 → Sort (max (u + 1) u_1)