YES Problem: a(x) -> x a(b(x)) -> c(b(b(a(a(x))))) b(x) -> c(x) c(c(x)) -> x Proof: Church Rosser Transformation Processor: b(x75) -> c(x75) c(c(x79)) -> x79 a(x81) -> x81 critical peaks: joinable Matrix Interpretation Processor: dim=1 interpretation: [b](x0) = x0, [a](x0) = x0 + 1, [c](x0) = x0 orientation: b(x75) = x75 >= x75 = c(x75) c(c(x79)) = x79 >= x79 = x79 a(x81) = x81 + 1 >= x81 = x81 problem: b(x75) -> c(x75) c(c(x79)) -> x79 Matrix Interpretation Processor: dim=1 interpretation: [b](x0) = 4x0 + 4, [c](x0) = 2x0 + 4 orientation: b(x75) = 4x75 + 4 >= 2x75 + 4 = c(x75) c(c(x79)) = 4x79 + 12 >= x79 = x79 problem: b(x75) -> c(x75) Matrix Interpretation Processor: dim=1 interpretation: [b](x0) = 4x0 + 1, [c](x0) = 4x0 orientation: b(x75) = 4x75 + 1 >= 4x75 = c(x75) problem: Qed