{α : Type} →
  {inst : Hashable α} →
    {inst_1 : BEq α} →
      {P : Sort u} →
        {elems : Array α} →
          {set : Std.HashSet α} →
            {elems' : Array α} →
              {set' : Std.HashSet α} →
                { elems := elems, set := set } = { elems := elems', set := set' } →
                  (elems ≍ elems' → set ≍ set' → P) → P