YES Proof: This system is quasi-decreasing. By \cite{O02}, p. 214, Proposition 7.2.50. This system is of type 3 or smaller. This system is deterministic. System R transformed to U(R). Call external tool: ttt2 - trs 30 Input: ssp(nil, 0) -> nil ?3(xs, y, ys', v) -> xs ssp(cons(y, ys'), v) -> ?3(ssp(ys', v), y, ys', v) ?2(xs', y, ys', v, w) -> cons(y, xs') ?1(w, y, ys', v) -> ?2(ssp(ys', w), y, ys', v, w) ssp(cons(y, ys'), v) -> ?1(sub(v, y), y, ys', v) sub(z, 0) -> z ?4(z, v, w) -> z sub(s(v), s(w)) -> ?4(sub(v, w), v, w) DP Processor: DPs: ssp#(cons(y,ys'),v) -> ssp#(ys',v) ssp#(cons(y,ys'),v) -> ?3#(ssp(ys',v),y,ys',v) ?1#(w,y,ys',v) -> ssp#(ys',w) ?1#(w,y,ys',v) -> ?2#(ssp(ys',w),y,ys',v,w) ssp#(cons(y,ys'),v) -> sub#(v,y) ssp#(cons(y,ys'),v) -> ?1#(sub(v,y),y,ys',v) sub#(s(v),s(w)) -> sub#(v,w) sub#(s(v),s(w)) -> ?4#(sub(v,w),v,w) TRS: ssp(nil(),0()) -> nil() ?3(xs,y,ys',v) -> xs ssp(cons(y,ys'),v) -> ?3(ssp(ys',v),y,ys',v) ?2(xs',y,ys',v,w) -> cons(y,xs') ?1(w,y,ys',v) -> ?2(ssp(ys',w),y,ys',v,w) ssp(cons(y,ys'),v) -> ?1(sub(v,y),y,ys',v) sub(z,0()) -> z ?4(z,v,w) -> z sub(s(v),s(w)) -> ?4(sub(v,w),v,w) TDG Processor: DPs: ssp#(cons(y,ys'),v) -> ssp#(ys',v) ssp#(cons(y,ys'),v) -> ?3#(ssp(ys',v),y,ys',v) ?1#(w,y,ys',v) -> ssp#(ys',w) ?1#(w,y,ys',v) -> ?2#(ssp(ys',w),y,ys',v,w) ssp#(cons(y,ys'),v) -> sub#(v,y) ssp#(cons(y,ys'),v) -> ?1#(sub(v,y),y,ys',v) sub#(s(v),s(w)) -> sub#(v,w) sub#(s(v),s(w)) -> ?4#(sub(v,w),v,w) TRS: ssp(nil(),0()) -> nil() ?3(xs,y,ys',v) -> xs ssp(cons(y,ys'),v) -> ?3(ssp(ys',v),y,ys',v) ?2(xs',y,ys',v,w) -> cons(y,xs') ?1(w,y,ys',v) -> ?2(ssp(ys',w),y,ys',v,w) ssp(cons(y,ys'),v) -> ?1(sub(v,y),y,ys',v) sub(z,0()) -> z ?4(z,v,w) -> z sub(s(v),s(w)) -> ?4(sub(v,w),v,w) graph: sub#(s(v),s(w)) -> sub#(v,w) -> sub#(s(v),s(w)) -> ?4#(sub(v,w),v,w) sub#(s(v),s(w)) -> sub#(v,w) -> sub#(s(v),s(w)) -> sub#(v,w) ?1#(w,y,ys',v) -> ssp#(ys',w) -> ssp#(cons(y,ys'),v) -> ?1#(sub(v,y),y,ys',v) ?1#(w,y,ys',v) -> ssp#(ys',w) -> ssp#(cons(y,ys'),v) -> sub#(v,y) ?1#(w,y,ys',v) -> ssp#(ys',w) -> ssp#(cons(y,ys'),v) -> ?3#(ssp(ys',v),y,ys',v) ?1#(w,y,ys',v) -> ssp#(ys',w) -> ssp#(cons(y,ys'),v) -> ssp#(ys',v) ssp#(cons(y,ys'),v) -> sub#(v,y) -> sub#(s(v),s(w)) -> ?4#(sub(v,w),v,w) ssp#(cons(y,ys'),v) -> sub#(v,y) -> sub#(s(v),s(w)) -> sub#(v,w) ssp#(cons(y,ys'),v) -> ?1#(sub(v,y),y,ys',v) -> ?1#(w,y,ys',v) -> ?2#(ssp(ys',w),y,ys',v,w) ssp#(cons(y,ys'),v) -> ?1#(sub(v,y),y,ys',v) -> ?1#(w,y,ys',v) -> ssp#(ys',w) ssp#(cons(y,ys'),v) -> ssp#(ys',v) -> ssp#(cons(y,ys'),v) -> ?1#(sub(v,y),y,ys',v) ssp#(cons(y,ys'),v) -> ssp#(ys',v) -> ssp#(cons(y,ys'),v) -> sub#(v,y) ssp#(cons(y,ys'),v) -> ssp#(ys',v) -> ssp#(cons(y,ys'),v) -> ?3#(ssp(ys',v),y,ys',v) ssp#(cons(y,ys'),v) -> ssp#(ys',v) -> ssp#(cons(y,ys'),v) -> ssp#(ys',v) SCC Processor: #sccs: 2 #rules: 4 #arcs: 14/64 DPs: ?1#(w,y,ys',v) -> ssp#(ys',w) ssp#(cons(y,ys'),v) -> ssp#(ys',v) ssp#(cons(y,ys'),v) -> ?1#(sub(v,y),y,ys',v) TRS: ssp(nil(),0()) -> nil() ?3(xs,y,ys',v) -> xs ssp(cons(y,ys'),v) -> ?3(ssp(ys',v),y,ys',v) ?2(xs',y,ys',v,w) -> cons(y,xs') ?1(w,y,ys',v) -> ?2(ssp(ys',w),y,ys',v,w) ssp(cons(y,ys'),v) -> ?1(sub(v,y),y,ys',v) sub(z,0()) -> z ?4(z,v,w) -> z sub(s(v),s(w)) -> ?4(sub(v,w),v,w) Subterm Criterion Processor: simple projection: pi(ssp#) = 0 pi(?1#) = 2 problem: DPs: ?1#(w,y,ys',v) -> ssp#(ys',w) TRS: ssp(nil(),0()) -> nil() ?3(xs,y,ys',v) -> xs ssp(cons(y,ys'),v) -> ?3(ssp(ys',v),y,ys',v) ?2(xs',y,ys',v,w) -> cons(y,xs') ?1(w,y,ys',v) -> ?2(ssp(ys',w),y,ys',v,w) ssp(cons(y,ys'),v) -> ?1(sub(v,y),y,ys',v) sub(z,0()) -> z ?4(z,v,w) -> z sub(s(v),s(w)) -> ?4(sub(v,w),v,w) SCC Processor: #sccs: 0 #rules: 0 #arcs: 5/1 DPs: sub#(s(v),s(w)) -> sub#(v,w) TRS: ssp(nil(),0()) -> nil() ?3(xs,y,ys',v) -> xs ssp(cons(y,ys'),v) -> ?3(ssp(ys',v),y,ys',v) ?2(xs',y,ys',v,w) -> cons(y,xs') ?1(w,y,ys',v) -> ?2(ssp(ys',w),y,ys',v,w) ssp(cons(y,ys'),v) -> ?1(sub(v,y),y,ys',v) sub(z,0()) -> z ?4(z,v,w) -> z sub(s(v),s(w)) -> ?4(sub(v,w),v,w) Subterm Criterion Processor: simple projection: pi(sub#) = 0 problem: DPs: TRS: ssp(nil(),0()) -> nil() ?3(xs,y,ys',v) -> xs ssp(cons(y,ys'),v) -> ?3(ssp(ys',v),y,ys',v) ?2(xs',y,ys',v,w) -> cons(y,xs') ?1(w,y,ys',v) -> ?2(ssp(ys',w),y,ys',v,w) ssp(cons(y,ys'),v) -> ?1(sub(v,y),y,ys',v) sub(z,0()) -> z ?4(z,v,w) -> z sub(s(v),s(w)) -> ?4(sub(v,w),v,w) Qed