Problem: f(x,x) -> f(g(x),g(x)) f(x,y) -> f(h(x),h(y)) g(x) -> p(x) h(x) -> p(x) Proof: Church Rosser Transformation Processor: strict: weak: critical peaks: 2 f(g(y),g(y)) <-0|[]- f(y,y) -1|[]-> f(h(y),h(y)) f(h(x),h(x)) <-1|[]- f(x,x) -0|[]-> f(g(x),g(x)) Redundant Rules Transformation: f(x,y) -> f(h(x),h(y)) g(x) -> p(x) h(x) -> p(x) Qed (ToyamaOyamaguchi95Cor22)