Verification algorithm for Lopatynsky condition

Source abstract

Authors studied the Lopatynsky condition to single out among properly elliptic differential equations in the Douglis–Nirenberg sense those ones with given boundary conditions that generate an elliptic problem. This condition can be written in various ways, in particular, in algebraic form also. A new algebraic formulation of this condition is found and an algorithm for its verification is presented. Examples of its verification are given as well.