∀ {K : Type u} [inst : NontriviallyNormedField K] {L : Type v} [inst_1 : Field L] [inst_2 : Algebra K L]
  [inst_3 : Algebra.IsAlgebraic K L] [hu : IsUltrametricDist K] [inst_4 : CompleteSpace K] (x : L),
  spectralNorm K L x = (spectralMulAlgNorm K L) x