Problem: a(f(x),y) -> f(a(f(y),x)) a(b(x),y) -> a(x,b(x)) a(g(x),x) -> g(b(g(x))) Proof: Church Rosser Transformation Processor (to relative problem): strict: a(f(x),y) -> f(a(f(y),x)) a(b(x),y) -> a(x,b(x)) a(g(x),x) -> g(b(g(x))) weak: original problem: a(f(x),y) -> f(a(f(y),x)) a(b(x),y) -> a(x,b(x)) a(g(x),x) -> g(b(g(x))) critical peaks: Matrix Interpretation Processor: dim=2 interpretation: [1 0] [1] [g](x0) = [0 0]x0 + [0], [1 0] [0] [b](x0) = [2 2]x0 + [1], [1 1] [2 0] [1] [a](x0, x1) = [1 1]x0 + [2 0]x1 + [2], [1 0] [0] [f](x0) = [1 0]x0 + [1] orientation: [2 0] [2 0] [2] [2 0] [2 0] [2] a(f(x),y) = [2 0]x + [2 0]y + [3] >= [2 0]x + [2 0]y + [3] = f(a(f(y),x)) [3 2] [2 0] [2] [3 1] [1] a(b(x),y) = [3 2]x + [2 0]y + [3] >= [3 1]x + [2] = a(x,b(x)) [3 0] [2] [1 0] [2] a(g(x),x) = [3 0]x + [3] >= [0 0]x + [0] = g(b(g(x))) problem: strict: a(f(x),y) -> f(a(f(y),x)) a(g(x),x) -> g(b(g(x))) weak: original problem: a(f(x),y) -> f(a(f(y),x)) a(b(x),y) -> a(x,b(x)) a(g(x),x) -> g(b(g(x))) Matrix Interpretation Processor: dim=1 interpretation: [g](x0) = x0 + 4, [b](x0) = x0 + 4, [a](x0, x1) = 2x0 + 2x1 + 6, [f](x0) = x0 orientation: a(f(x),y) = 2x + 2y + 6 >= 2x + 2y + 6 = f(a(f(y),x)) a(g(x),x) = 4x + 14 >= x + 12 = g(b(g(x))) problem: strict: a(f(x),y) -> f(a(f(y),x)) weak: original problem: a(f(x),y) -> f(a(f(y),x)) a(b(x),y) -> a(x,b(x)) a(g(x),x) -> g(b(g(x))) KH confluence processor Split input TRS into two TRSs S and T: TRS S: a(f(x),y) -> f(a(f(y),x)) TRS T: a(b(x),y) -> a(x,b(x)) a(g(x),x) -> g(b(g(x))) As established above, T/S is terminating. T is strongly non-overlapping on S and S is strongly non-overlapping on T Please install theorem prover 'Prover9' and 'Mace4' for handling more TRSs. All S-critical pairs are joinable. We have to check confluence of S. Church Rosser Transformation Processor (no redundant rules): strict: a(f(x),y) -> f(a(f(y),x)) weak: critical peaks: 0 Closedness Processor (*feeble*): Qed