YES Problem: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) log(x) -> log2(x,0()) log2(x,y) -> if(le(x,s(0())),x,inc(y)) if(true(),x,s(y)) -> y if(false(),x,y) -> log2(half(x),y) Proof: DP Processor: DPs: half#(s(s(x))) -> half#(x) le#(s(x),s(y)) -> le#(x,y) inc#(s(x)) -> inc#(x) log#(x) -> log2#(x,0()) log2#(x,y) -> inc#(y) log2#(x,y) -> le#(x,s(0())) log2#(x,y) -> if#(le(x,s(0())),x,inc(y)) if#(false(),x,y) -> half#(x) if#(false(),x,y) -> log2#(half(x),y) TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) log(x) -> log2(x,0()) log2(x,y) -> if(le(x,s(0())),x,inc(y)) if(true(),x,s(y)) -> y if(false(),x,y) -> log2(half(x),y) Matrix Interpretation Processor: dim=1 interpretation: [if#](x0, x1, x2) = 1/2x0 + x1 + 2x2, [log2#](x0, x1) = 2x0 + 2x1 + 1/2, [log#](x0) = 2x0 + 1, [inc#](x0) = 1/2x0, [le#](x0, x1) = 2x0, [half#](x0) = 1/2x0 + 1/2, [if](x0, x1, x2) = x1 + x2, [log2](x0, x1) = 2x0 + x1, [log](x0) = 3x0, [inc](x0) = x0, [false] = 2, [true] = 0, [le](x0, x1) = 2x0, [s](x0) = x0 + 1, [half](x0) = 1/2x0, [0] = 0 orientation: half#(s(s(x))) = 1/2x + 3/2 >= 1/2x + 1/2 = half#(x) le#(s(x),s(y)) = 2x + 2 >= 2x = le#(x,y) inc#(s(x)) = 1/2x + 1/2 >= 1/2x = inc#(x) log#(x) = 2x + 1 >= 2x + 1/2 = log2#(x,0()) log2#(x,y) = 2x + 2y + 1/2 >= 1/2y = inc#(y) log2#(x,y) = 2x + 2y + 1/2 >= 2x = le#(x,s(0())) log2#(x,y) = 2x + 2y + 1/2 >= 2x + 2y = if#(le(x,s(0())),x,inc(y)) if#(false(),x,y) = x + 2y + 1 >= 1/2x + 1/2 = half#(x) if#(false(),x,y) = x + 2y + 1 >= x + 2y + 1/2 = log2#(half(x),y) half(0()) = 0 >= 0 = 0() half(s(0())) = 1/2 >= 0 = 0() half(s(s(x))) = 1/2x + 1 >= 1/2x + 1 = s(half(x)) le(0(),y) = 0 >= 0 = true() le(s(x),0()) = 2x + 2 >= 2 = false() le(s(x),s(y)) = 2x + 2 >= 2x = le(x,y) inc(0()) = 0 >= 0 = 0() inc(s(x)) = x + 1 >= x + 1 = s(inc(x)) log(x) = 3x >= 2x = log2(x,0()) log2(x,y) = 2x + y >= x + y = if(le(x,s(0())),x,inc(y)) if(true(),x,s(y)) = x + y + 1 >= y = y if(false(),x,y) = x + y >= x + y = log2(half(x),y) problem: DPs: TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) log(x) -> log2(x,0()) log2(x,y) -> if(le(x,s(0())),x,inc(y)) if(true(),x,s(y)) -> y if(false(),x,y) -> log2(half(x),y) Qed