YES Problem: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() p(0()) -> 0() p(s(x)) -> x bits(x) -> bitIter(x,0()) bitIter(x,y) -> if(zero(x),x,inc(y)) if(true(),x,y) -> p(y) if(false(),x,y) -> bitIter(half(x),y) Proof: DP Processor: DPs: half#(s(s(x))) -> half#(x) inc#(s(x)) -> inc#(x) bits#(x) -> bitIter#(x,0()) bitIter#(x,y) -> inc#(y) bitIter#(x,y) -> zero#(x) bitIter#(x,y) -> if#(zero(x),x,inc(y)) if#(true(),x,y) -> p#(y) if#(false(),x,y) -> half#(x) if#(false(),x,y) -> bitIter#(half(x),y) TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() p(0()) -> 0() p(s(x)) -> x bits(x) -> bitIter(x,0()) bitIter(x,y) -> if(zero(x),x,inc(y)) if(true(),x,y) -> p(y) if(false(),x,y) -> bitIter(half(x),y) Usable Rule Processor: DPs: half#(s(s(x))) -> half#(x) inc#(s(x)) -> inc#(x) bits#(x) -> bitIter#(x,0()) bitIter#(x,y) -> inc#(y) bitIter#(x,y) -> zero#(x) bitIter#(x,y) -> if#(zero(x),x,inc(y)) if#(true(),x,y) -> p#(y) if#(false(),x,y) -> half#(x) if#(false(),x,y) -> bitIter#(half(x),y) TRS: inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) Matrix Interpretation Processor: dim=1 usable rules: inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) interpretation: [if#](x0, x1, x2) = 1/2x0 + x1 + 1/2x2 + 1/2, [bitIter#](x0, x1) = 2x0 + 1/2x1 + 1, [bits#](x0) = 3x0 + 3/2, [p#](x0) = 1/2x0, [zero#](x0) = 0, [inc#](x0) = 1/2x0, [half#](x0) = x0, [false] = 2, [true] = 0, [zero](x0) = 2x0, [inc](x0) = x0, [s](x0) = x0 + 2, [half](x0) = 1/2x0, [0] = 0 orientation: half#(s(s(x))) = x + 4 >= x = half#(x) inc#(s(x)) = 1/2x + 1 >= 1/2x = inc#(x) bits#(x) = 3x + 3/2 >= 2x + 1 = bitIter#(x,0()) bitIter#(x,y) = 2x + 1/2y + 1 >= 1/2y = inc#(y) bitIter#(x,y) = 2x + 1/2y + 1 >= 0 = zero#(x) bitIter#(x,y) = 2x + 1/2y + 1 >= 2x + 1/2y + 1/2 = if#(zero(x),x,inc(y)) if#(true(),x,y) = x + 1/2y + 1/2 >= 1/2y = p#(y) if#(false(),x,y) = x + 1/2y + 3/2 >= x = half#(x) if#(false(),x,y) = x + 1/2y + 3/2 >= x + 1/2y + 1 = bitIter#(half(x),y) inc(0()) = 0 >= 0 = 0() inc(s(x)) = x + 2 >= x + 2 = s(inc(x)) zero(0()) = 0 >= 0 = true() zero(s(x)) = 2x + 4 >= 2 = false() half(0()) = 0 >= 0 = 0() half(s(0())) = 1 >= 0 = 0() half(s(s(x))) = 1/2x + 2 >= 1/2x + 2 = s(half(x)) problem: DPs: TRS: inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) Qed