YES Problem: :(x,x) -> e() :(x,e()) -> x i(:(x,y)) -> :(y,x) :(:(x,y),z) -> :(x,:(z,i(y))) :(e(),x) -> i(x) i(i(x)) -> x i(e()) -> e() :(x,:(y,i(x))) -> i(y) :(x,:(y,:(i(x),z))) -> :(i(z),y) :(i(x),:(y,x)) -> i(y) :(i(x),:(y,:(x,z))) -> :(i(z),y) Proof: DP Processor: DPs: i#(:(x,y)) -> :#(y,x) :#(:(x,y),z) -> i#(y) :#(:(x,y),z) -> :#(z,i(y)) :#(:(x,y),z) -> :#(x,:(z,i(y))) :#(e(),x) -> i#(x) :#(x,:(y,i(x))) -> i#(y) :#(x,:(y,:(i(x),z))) -> i#(z) :#(x,:(y,:(i(x),z))) -> :#(i(z),y) :#(i(x),:(y,x)) -> i#(y) :#(i(x),:(y,:(x,z))) -> i#(z) :#(i(x),:(y,:(x,z))) -> :#(i(z),y) TRS: :(x,x) -> e() :(x,e()) -> x i(:(x,y)) -> :(y,x) :(:(x,y),z) -> :(x,:(z,i(y))) :(e(),x) -> i(x) i(i(x)) -> x i(e()) -> e() :(x,:(y,i(x))) -> i(y) :(x,:(y,:(i(x),z))) -> :(i(z),y) :(i(x),:(y,x)) -> i(y) :(i(x),:(y,:(x,z))) -> :(i(z),y) KBO Processor: argument filtering: pi(:) = [0,1] pi(e) = [] pi(i) = [0] pi(:#) = [0,1] pi(i#) = 0 usable rules: :(x,x) -> e() :(x,e()) -> x i(:(x,y)) -> :(y,x) :(:(x,y),z) -> :(x,:(z,i(y))) :(e(),x) -> i(x) i(i(x)) -> x i(e()) -> e() :(x,:(y,i(x))) -> i(y) :(x,:(y,:(i(x),z))) -> :(i(z),y) :(i(x),:(y,x)) -> i(y) :(i(x),:(y,:(x,z))) -> :(i(z),y) weight function: w0 = 1 w(i#) = w(e) = 1 w(:#) = w(i) = w(:) = 0 precedence: i > : > i# ~ :# ~ e problem: DPs: TRS: :(x,x) -> e() :(x,e()) -> x i(:(x,y)) -> :(y,x) :(:(x,y),z) -> :(x,:(z,i(y))) :(e(),x) -> i(x) i(i(x)) -> x i(e()) -> e() :(x,:(y,i(x))) -> i(y) :(x,:(y,:(i(x),z))) -> :(i(z),y) :(i(x),:(y,x)) -> i(y) :(i(x),:(y,:(x,z))) -> :(i(z),y) Qed