∀ (K : Type u_1) [inst : NormedField K] (L : Type u_2) [inst_1 : Field L] [inst_2 : Algebra K L] [IsUltrametricDist K]
  [h_alg : Algebra.IsAlgebraic K L] (x x_1 : L), spectralNorm K L (x + x_1) ≤ spectralNorm K L x + spectralNorm K L x_1