PROVING INVERSE-POSITIVITY OF LINEAR OPERATORS BY REDUCTION
John Schroeder · 1969
Abstract : A method is presented to prove that a linear operator M is inverse- positive, i.e. Mu = or o implies u = or o. The method consists in reducing the problem for the given operator M to a simpler problem. Sometimes, iterated reductions are appropriate, for example, if M is a differential operator of higher order.