YES Problem: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) Proof: DP Processor: DPs: le#(s(x),s(y)) -> le#(x,y) minus#(s(x),s(y)) -> minus#(x,y) gcd#(s(x),s(y)) -> le#(y,x) gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) if_gcd#(true(),s(x),s(y)) -> minus#(x,y) if_gcd#(true(),s(x),s(y)) -> gcd#(minus(x,y),s(y)) if_gcd#(false(),s(x),s(y)) -> minus#(y,x) if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) TDG Processor: DPs: le#(s(x),s(y)) -> le#(x,y) minus#(s(x),s(y)) -> minus#(x,y) gcd#(s(x),s(y)) -> le#(y,x) gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) if_gcd#(true(),s(x),s(y)) -> minus#(x,y) if_gcd#(true(),s(x),s(y)) -> gcd#(minus(x,y),s(y)) if_gcd#(false(),s(x),s(y)) -> minus#(y,x) if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) graph: if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) -> gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) -> gcd#(s(x),s(y)) -> le#(y,x) if_gcd#(false(),s(x),s(y)) -> minus#(y,x) -> minus#(s(x),s(y)) -> minus#(x,y) if_gcd#(true(),s(x),s(y)) -> gcd#(minus(x,y),s(y)) -> gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) if_gcd#(true(),s(x),s(y)) -> gcd#(minus(x,y),s(y)) -> gcd#(s(x),s(y)) -> le#(y,x) if_gcd#(true(),s(x),s(y)) -> minus#(x,y) -> minus#(s(x),s(y)) -> minus#(x,y) gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) -> if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) -> if_gcd#(false(),s(x),s(y)) -> minus#(y,x) gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) -> if_gcd#(true(),s(x),s(y)) -> gcd#(minus(x,y),s(y)) gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) -> if_gcd#(true(),s(x),s(y)) -> minus#(x,y) gcd#(s(x),s(y)) -> le#(y,x) -> le#(s(x),s(y)) -> le#(x,y) minus#(s(x),s(y)) -> minus#(x,y) -> minus#(s(x),s(y)) -> minus#(x,y) le#(s(x),s(y)) -> le#(x,y) -> le#(s(x),s(y)) -> le#(x,y) SCC Processor: #sccs: 3 #rules: 5 #arcs: 13/64 DPs: if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) if_gcd#(true(),s(x),s(y)) -> gcd#(minus(x,y),s(y)) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) Arctic Interpretation Processor: dimension: 1 interpretation: [if_gcd#](x0, x1, x2) = x0 + 1x1 + x2, [gcd#](x0, x1) = 1x0 + x1, [if_gcd](x0, x1, x2) = x1 + x2 + 0, [gcd](x0, x1) = x0 + x1 + 0, [minus](x0, x1) = 2x0, [false] = 0, [s](x0) = 5x0, [true] = 0, [le](x0, x1) = x0 + x1, [0] = 7 orientation: if_gcd#(false(),s(x),s(y)) = 6x + 5y + 0 >= 5x + 3y = gcd#(minus(y,x),s(x)) gcd#(s(x),s(y)) = 6x + 5y >= 6x + 5y = if_gcd#(le(y,x),s(x),s(y)) if_gcd#(true(),s(x),s(y)) = 6x + 5y + 0 >= 3x + 5y = gcd#(minus(x,y),s(y)) le(0(),y) = y + 7 >= 0 = true() le(s(x),0()) = 5x + 7 >= 0 = false() le(s(x),s(y)) = 5x + 5y >= x + y = le(x,y) minus(x,0()) = 2x >= x = x minus(s(x),s(y)) = 7x >= 2x = minus(x,y) gcd(0(),y) = y + 7 >= y = y gcd(s(x),0()) = 5x + 7 >= 5x = s(x) gcd(s(x),s(y)) = 5x + 5y + 0 >= 5x + 5y + 0 = if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) = 5x + 5y + 0 >= 2x + 5y + 0 = gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) = 5x + 5y + 0 >= 5x + 2y + 0 = gcd(minus(y,x),s(x)) problem: DPs: gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) if_gcd#(true(),s(x),s(y)) -> gcd#(minus(x,y),s(y)) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) KBO Processor: argument filtering: pi(0) = [] pi(le) = [] pi(true) = [] pi(s) = [0] pi(false) = [] pi(minus) = 0 pi(gcd) = [0,1] pi(if_gcd) = [1,2] pi(gcd#) = 0 pi(if_gcd#) = 1 weight function: w0 = 1 w(if_gcd) = w(gcd) = w(minus) = w(false) = w(s) = w(true) = w( le) = w(0) = 1 w(if_gcd#) = w(gcd#) = 0 precedence: gcd ~ le > if_gcd# ~ gcd# ~ if_gcd ~ minus ~ false ~ s ~ true ~ 0 problem: DPs: gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) SCC Processor: #sccs: 0 #rules: 0 #arcs: 4/1 DPs: minus#(s(x),s(y)) -> minus#(x,y) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) Subterm Criterion Processor: simple projection: pi(minus#) = 1 problem: DPs: TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) Qed DPs: le#(s(x),s(y)) -> le#(x,y) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) Subterm Criterion Processor: simple projection: pi(le#) = 1 problem: DPs: TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(s(x),s(y)) -> minus(x,y) gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) Qed