Term Rewriting System R: [x, y, z] app(app(app(f, app(app(g, x), y)), x), z) -> app(app(app(f, z), z), z) app(app(g, x), y) -> x app(app(g, x), y) -> y Innermost Termination of R to be shown. Removing the following rules from R which left hand sides contain non normal subterms app(app(app(f, app(app(g, x), y)), x), z) -> app(app(app(f, z), z), z) Removing the following rules from R which fullfill a polynomial ordering: app(app(g, x), y) -> x app(app(g, x), y) -> y where the Polynomial interpretation: POL(g) = 1 POL(app(x_1, x_2)) = x_1 + x_2 was used. All Rules of R can be deleted. Innermost Termination of R successfully shown. Duration: 0.361 seconds.