YES(?,O(n^2)) Problem: app(id(),x) -> x app(plus(),0()) -> id() app(app(plus(),app(s(),x)),y) -> app(s(),app(app(plus(),x),y)) Proof: RT Transformation Processor: strict: app(id(),x) -> x app(plus(),0()) -> id() app(app(plus(),app(s(),x)),y) -> app(s(),app(app(plus(),x),y)) weak: Matrix Interpretation Processor: dimension: 1 interpretation: [s] = 12, [0] = 16, [plus] = 4, [app](x0, x1) = x0 + x1 + 5, [id] = 8 orientation: app(id(),x) = x + 13 >= x = x app(plus(),0()) = 25 >= 8 = id() app(app(plus(),app(s(),x)),y) = x + y + 31 >= x + y + 31 = app(s(),app(app(plus(),x),y)) problem: strict: app(app(plus(),app(s(),x)),y) -> app(s(),app(app(plus(),x),y)) weak: app(id(),x) -> x app(plus(),0()) -> id() Matrix Interpretation Processor: dimension: 2 interpretation: [0] [s] = [0], [4 ] [0] = [13], [0] [plus] = [0], [1 4] [0] [app](x0, x1) = [0 1]x0 + x1 + [2], [0] [id] = [0] orientation: [1 4] [16] [1 4] [8] app(app(plus(),app(s(),x)),y) = [0 1]x + y + [6 ] >= [0 1]x + y + [6] = app(s(),app(app(plus(),x),y)) [0] app(id(),x) = x + [2] >= x = x [4 ] [0] app(plus(),0()) = [15] >= [0] = id() problem: strict: weak: app(app(plus(),app(s(),x)),y) -> app(s(),app(app(plus(),x),y)) app(id(),x) -> x app(plus(),0()) -> id() Qed