ALEXANDRIA, Va., Dec. 2 -- United States Patent no. 12,487,591, issued on Dec. 2, was assigned to Siemens Industry Software NV (Leuven, Belgium).

"Ring-closures in fault trees and normalized representation" was invented by Kai Hofig (Rohrdorf, Germany), Francesco Montrone (Riemerling, Germany), Stefan Rothbauer (Augsburg, Germany) and Marc Zeller (Munich).

According to the abstract* released by the U.S. Patent & Trademark Office: "One or more ring closures of a fault tree are provided. For each one of the one or more ring closures: at least one respective edge the respective ring closure is replaced in the fault tree by a respective variable to obtain a placeholder fault tree and a normalized representation of the placeholder fault tree i...