YES Problem: rev1(0(),nil()) -> 0() rev1(s(X),nil()) -> s(X) rev1(X,cons(Y,L)) -> rev1(Y,L) rev(nil()) -> nil() rev(cons(X,L)) -> cons(rev1(X,L),rev2(X,L)) rev2(X,nil()) -> nil() rev2(X,cons(Y,L)) -> rev(cons(X,rev(rev2(Y,L)))) Proof: DP Processor: DPs: rev1#(X,cons(Y,L)) -> rev1#(Y,L) rev#(cons(X,L)) -> rev2#(X,L) rev#(cons(X,L)) -> rev1#(X,L) rev2#(X,cons(Y,L)) -> rev2#(Y,L) rev2#(X,cons(Y,L)) -> rev#(rev2(Y,L)) rev2#(X,cons(Y,L)) -> rev#(cons(X,rev(rev2(Y,L)))) TRS: rev1(0(),nil()) -> 0() rev1(s(X),nil()) -> s(X) rev1(X,cons(Y,L)) -> rev1(Y,L) rev(nil()) -> nil() rev(cons(X,L)) -> cons(rev1(X,L),rev2(X,L)) rev2(X,nil()) -> nil() rev2(X,cons(Y,L)) -> rev(cons(X,rev(rev2(Y,L)))) TDG Processor: DPs: rev1#(X,cons(Y,L)) -> rev1#(Y,L) rev#(cons(X,L)) -> rev2#(X,L) rev#(cons(X,L)) -> rev1#(X,L) rev2#(X,cons(Y,L)) -> rev2#(Y,L) rev2#(X,cons(Y,L)) -> rev#(rev2(Y,L)) rev2#(X,cons(Y,L)) -> rev#(cons(X,rev(rev2(Y,L)))) TRS: rev1(0(),nil()) -> 0() rev1(s(X),nil()) -> s(X) rev1(X,cons(Y,L)) -> rev1(Y,L) rev(nil()) -> nil() rev(cons(X,L)) -> cons(rev1(X,L),rev2(X,L)) rev2(X,nil()) -> nil() rev2(X,cons(Y,L)) -> rev(cons(X,rev(rev2(Y,L)))) graph: rev2#(X,cons(Y,L)) -> rev2#(Y,L) -> rev2#(X,cons(Y,L)) -> rev#(cons(X,rev(rev2(Y,L)))) rev2#(X,cons(Y,L)) -> rev2#(Y,L) -> rev2#(X,cons(Y,L)) -> rev#(rev2(Y,L)) rev2#(X,cons(Y,L)) -> rev2#(Y,L) -> rev2#(X,cons(Y,L)) -> rev2#(Y,L) rev2#(X,cons(Y,L)) -> rev#(rev2(Y,L)) -> rev#(cons(X,L)) -> rev1#(X,L) rev2#(X,cons(Y,L)) -> rev#(rev2(Y,L)) -> rev#(cons(X,L)) -> rev2#(X,L) rev2#(X,cons(Y,L)) -> rev#(cons(X,rev(rev2(Y,L)))) -> rev#(cons(X,L)) -> rev1#(X,L) rev2#(X,cons(Y,L)) -> rev#(cons(X,rev(rev2(Y,L)))) -> rev#(cons(X,L)) -> rev2#(X,L) rev#(cons(X,L)) -> rev2#(X,L) -> rev2#(X,cons(Y,L)) -> rev#(cons(X,rev(rev2(Y,L)))) rev#(cons(X,L)) -> rev2#(X,L) -> rev2#(X,cons(Y,L)) -> rev#(rev2(Y,L)) rev#(cons(X,L)) -> rev2#(X,L) -> rev2#(X,cons(Y,L)) -> rev2#(Y,L) rev#(cons(X,L)) -> rev1#(X,L) -> rev1#(X,cons(Y,L)) -> rev1#(Y,L) rev1#(X,cons(Y,L)) -> rev1#(Y,L) -> rev1#(X,cons(Y,L)) -> rev1#(Y,L) SCC Processor: #sccs: 2 #rules: 5 #arcs: 12/36 DPs: rev2#(X,cons(Y,L)) -> rev2#(Y,L) rev2#(X,cons(Y,L)) -> rev#(rev2(Y,L)) rev#(cons(X,L)) -> rev2#(X,L) rev2#(X,cons(Y,L)) -> rev#(cons(X,rev(rev2(Y,L)))) TRS: rev1(0(),nil()) -> 0() rev1(s(X),nil()) -> s(X) rev1(X,cons(Y,L)) -> rev1(Y,L) rev(nil()) -> nil() rev(cons(X,L)) -> cons(rev1(X,L),rev2(X,L)) rev2(X,nil()) -> nil() rev2(X,cons(Y,L)) -> rev(cons(X,rev(rev2(Y,L)))) Arctic Interpretation Processor: dimension: 1 interpretation: [rev2#](x0, x1) = x1, [rev#](x0) = x0 + 0, [rev2](x0, x1) = x1, [rev](x0) = x0, [cons](x0, x1) = 2x1 + 0, [s](x0) = 0, [rev1](x0, x1) = 2, [nil] = 6, [0] = 1 orientation: rev2#(X,cons(Y,L)) = 2L + 0 >= L = rev2#(Y,L) rev2#(X,cons(Y,L)) = 2L + 0 >= L + 0 = rev#(rev2(Y,L)) rev#(cons(X,L)) = 2L + 0 >= L = rev2#(X,L) rev2#(X,cons(Y,L)) = 2L + 0 >= 2L + 0 = rev#(cons(X,rev(rev2(Y,L)))) rev1(0(),nil()) = 2 >= 1 = 0() rev1(s(X),nil()) = 2 >= 0 = s(X) rev1(X,cons(Y,L)) = 2 >= 2 = rev1(Y,L) rev(nil()) = 6 >= 6 = nil() rev(cons(X,L)) = 2L + 0 >= 2L + 0 = cons(rev1(X,L),rev2(X,L)) rev2(X,nil()) = 6 >= 6 = nil() rev2(X,cons(Y,L)) = 2L + 0 >= 2L + 0 = rev(cons(X,rev(rev2(Y,L)))) problem: DPs: rev2#(X,cons(Y,L)) -> rev#(rev2(Y,L)) rev2#(X,cons(Y,L)) -> rev#(cons(X,rev(rev2(Y,L)))) TRS: rev1(0(),nil()) -> 0() rev1(s(X),nil()) -> s(X) rev1(X,cons(Y,L)) -> rev1(Y,L) rev(nil()) -> nil() rev(cons(X,L)) -> cons(rev1(X,L),rev2(X,L)) rev2(X,nil()) -> nil() rev2(X,cons(Y,L)) -> rev(cons(X,rev(rev2(Y,L)))) SCC Processor: #sccs: 0 #rules: 0 #arcs: 8/4 DPs: rev1#(X,cons(Y,L)) -> rev1#(Y,L) TRS: rev1(0(),nil()) -> 0() rev1(s(X),nil()) -> s(X) rev1(X,cons(Y,L)) -> rev1(Y,L) rev(nil()) -> nil() rev(cons(X,L)) -> cons(rev1(X,L),rev2(X,L)) rev2(X,nil()) -> nil() rev2(X,cons(Y,L)) -> rev(cons(X,rev(rev2(Y,L)))) Subterm Criterion Processor: simple projection: pi(rev1#) = 1 problem: DPs: TRS: rev1(0(),nil()) -> 0() rev1(s(X),nil()) -> s(X) rev1(X,cons(Y,L)) -> rev1(Y,L) rev(nil()) -> nil() rev(cons(X,L)) -> cons(rev1(X,L),rev2(X,L)) rev2(X,nil()) -> nil() rev2(X,cons(Y,L)) -> rev(cons(X,rev(rev2(Y,L)))) Qed