∀ (K : Type u_1) [inst : NormedField K] (L : Type u_2) [inst_1 : Field L] [inst_2 : Algebra K L]
  [h_fin : FiniteDimensional K L] [hn : Normal K L] [IsUltrametricDist K] (x y : L),
  spectralNorm K L (x * y) ≤ spectralNorm K L x * spectralNorm K L y