Direct Method of Obtaining Capacitance from Finite-Element Matrices (Clarification)

In the letter by Daly and Helps, they suggest that energy can be minimized on an element-by-element basis. The functional, however, must be treated globally because energy minimization has meaning only over the whole system. TM discussion follows Daly and Helps´ reasoning, but on a global basis, and draws different conclusions based on our work with finite elements.