It is shown that recent perturbation theorems for the joint spectrum of commuting matrices, which have been proved using Clifford-algebra tools, can be obtained and improved by classical means, as used in the case of the standard eigenvalue problem.
It is shown that recent perturbation theorems for the joint spectrum of commuting matrices, which have been proved using Clifford-algebra tools, can be obtained and improved by classical means, as used in the case of the standard eigenvalue problem.