YES Problem: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(0(),y) -> 0() mod(s(x),0()) -> 0() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) Proof: DP Processor: DPs: le#(s(x),s(y)) -> le#(x,y) minus#(s(x),y) -> le#(s(x),y) minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) if_minus#(false(),s(x),y) -> minus#(x,y) mod#(s(x),s(y)) -> le#(y,x) mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) if_mod#(true(),s(x),s(y)) -> minus#(x,y) if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(0(),y) -> 0() mod(s(x),0()) -> 0() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) TDG Processor: DPs: le#(s(x),s(y)) -> le#(x,y) minus#(s(x),y) -> le#(s(x),y) minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) if_minus#(false(),s(x),y) -> minus#(x,y) mod#(s(x),s(y)) -> le#(y,x) mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) if_mod#(true(),s(x),s(y)) -> minus#(x,y) if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(0(),y) -> 0() mod(s(x),0()) -> 0() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) graph: if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) -> mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) -> mod#(s(x),s(y)) -> le#(y,x) if_mod#(true(),s(x),s(y)) -> minus#(x,y) -> minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) if_mod#(true(),s(x),s(y)) -> minus#(x,y) -> minus#(s(x),y) -> le#(s(x),y) mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) -> if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) -> if_mod#(true(),s(x),s(y)) -> minus#(x,y) mod#(s(x),s(y)) -> le#(y,x) -> le#(s(x),s(y)) -> le#(x,y) if_minus#(false(),s(x),y) -> minus#(x,y) -> minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) if_minus#(false(),s(x),y) -> minus#(x,y) -> minus#(s(x),y) -> le#(s(x),y) minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) -> if_minus#(false(),s(x),y) -> minus#(x,y) minus#(s(x),y) -> le#(s(x),y) -> le#(s(x),s(y)) -> le#(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: 12/64 DPs: if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) mod#(s(x),s(y)) -> if_mod#(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(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(0(),y) -> 0() mod(s(x),0()) -> 0() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) Usable Rule Processor: DPs: if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) TRS: minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) le(0(),y) -> true() Arctic Interpretation Processor: dimension: 1 usable rules: minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) le(0(),y) -> true() interpretation: [if_mod#](x0, x1, x2) = -4x0 + 2x1, [mod#](x0, x1) = 3x0 + 1, [if_minus](x0, x1, x2) = -8x0 + x1 + -4, [minus](x0, x1) = x0 + -3, [false] = 3, [s](x0) = 3x0 + 0, [true] = 3, [le](x0, x1) = 4, [0] = 0 orientation: if_mod#(true(),s(x),s(y)) = 5x + 2 >= 3x + 1 = mod#(minus(x,y),s(y)) mod#(s(x),s(y)) = 6x + 3 >= 5x + 2 = if_mod#(le(y,x),s(x),s(y)) minus(0(),y) = 0 >= 0 = 0() minus(s(x),y) = 3x + 0 >= 3x + 0 = if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) = 3x + 0 >= 0 = 0() if_minus(false(),s(x),y) = 3x + 0 >= 3x + 0 = s(minus(x,y)) le(s(x),0()) = 4 >= 3 = false() le(s(x),s(y)) = 4 >= 4 = le(x,y) le(0(),y) = 4 >= 3 = true() problem: DPs: TRS: minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) le(0(),y) -> true() Qed DPs: minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) if_minus#(false(),s(x),y) -> minus#(x,y) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(0(),y) -> 0() mod(s(x),0()) -> 0() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) Subterm Criterion Processor: simple projection: pi(minus#) = 0 pi(if_minus#) = 1 problem: DPs: minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(0(),y) -> 0() mod(s(x),0()) -> 0() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) SCC Processor: #sccs: 0 #rules: 0 #arcs: 2/1 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(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(0(),y) -> 0() mod(s(x),0()) -> 0() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) Subterm Criterion Processor: simple projection: pi(le#) = 0 problem: DPs: TRS: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(0(),y) -> 0() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> 0() if_minus(false(),s(x),y) -> s(minus(x,y)) mod(0(),y) -> 0() mod(s(x),0()) -> 0() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) Qed