Sort u →
  {E : Type u_1} →
    [inst : NormedAddCommGroup E] →
      [inst_1 : NormedSpace ℂ E] →
        StrongFEPair E →
          {E' : Type u_1} → [inst' : NormedAddCommGroup E'] → [inst'_1 : NormedSpace ℂ E'] → StrongFEPair E' → Sort u