YES Problem: *(+(x,y),z) -> +(*(x,z),*(y,z)) +(x,y) -> +(y,x) Proof: Church Rosser Transformation Processor (okui): simultaneous critical peaks: *(+(y,x),z) <-[0]- *(+(x,y),z) -[]-> +(*(x,z),*(y,z)) +(*(x,x69),*(y,x69)) <-[]- *(+(x,y),x69) -[0]-> *(+(y,x),x69) joinable Qed