YES We show the termination of the TRS R: first(|0|(),X) -> nil() first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) from(X) -> cons(X,n__from(n__s(X))) first(X1,X2) -> n__first(X1,X2) from(X) -> n__from(X) s(X) -> n__s(X) activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) activate(n__from(X)) -> from(activate(X)) activate(n__s(X)) -> s(activate(X)) activate(X) -> X -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: first#(s(X),cons(Y,Z)) -> activate#(Z) p2: activate#(n__first(X1,X2)) -> first#(activate(X1),activate(X2)) p3: activate#(n__first(X1,X2)) -> activate#(X1) p4: activate#(n__first(X1,X2)) -> activate#(X2) p5: activate#(n__from(X)) -> from#(activate(X)) p6: activate#(n__from(X)) -> activate#(X) p7: activate#(n__s(X)) -> s#(activate(X)) p8: activate#(n__s(X)) -> activate#(X) and R consists of: r1: first(|0|(),X) -> nil() r2: first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) r3: from(X) -> cons(X,n__from(n__s(X))) r4: first(X1,X2) -> n__first(X1,X2) r5: from(X) -> n__from(X) r6: s(X) -> n__s(X) r7: activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) r8: activate(n__from(X)) -> from(activate(X)) r9: activate(n__s(X)) -> s(activate(X)) r10: activate(X) -> X The estimated dependency graph contains the following SCCs: {p1, p2, p3, p4, p6, p8} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: first#(s(X),cons(Y,Z)) -> activate#(Z) p2: activate#(n__s(X)) -> activate#(X) p3: activate#(n__from(X)) -> activate#(X) p4: activate#(n__first(X1,X2)) -> activate#(X2) p5: activate#(n__first(X1,X2)) -> activate#(X1) p6: activate#(n__first(X1,X2)) -> first#(activate(X1),activate(X2)) and R consists of: r1: first(|0|(),X) -> nil() r2: first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) r3: from(X) -> cons(X,n__from(n__s(X))) r4: first(X1,X2) -> n__first(X1,X2) r5: from(X) -> n__from(X) r6: s(X) -> n__s(X) r7: activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) r8: activate(n__from(X)) -> from(activate(X)) r9: activate(n__s(X)) -> s(activate(X)) r10: activate(X) -> X The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: first#_A(x1,x2) = ((0,0),(1,0)) x1 + ((0,0),(1,0)) x2 + (1,7) s_A(x1) = ((1,0),(0,0)) x1 + (0,5) cons_A(x1,x2) = ((1,0),(1,0)) x2 activate#_A(x1) = ((0,0),(1,0)) x1 + (1,4) n__s_A(x1) = ((1,0),(0,0)) x1 + (0,1) n__from_A(x1) = ((1,0),(1,1)) x1 + (3,10) n__first_A(x1,x2) = ((1,0),(1,0)) x1 + ((1,0),(1,0)) x2 + (4,6) activate_A(x1) = ((1,0),(1,1)) x1 + (0,9) first_A(x1,x2) = ((1,0),(1,0)) x1 + ((1,0),(1,0)) x2 + (4,10) |0|_A() = (1,1) nil_A() = (2,2) from_A(x1) = ((1,0),(1,1)) x1 + (3,12) precedence: first# = nil > n__from = activate = |0| = from > s = n__s = first > activate# = n__first > cons partial status: pi(first#) = [] pi(s) = [] pi(cons) = [] pi(activate#) = [] pi(n__s) = [] pi(n__from) = [1] pi(n__first) = [] pi(activate) = [1] pi(first) = [] pi(|0|) = [] pi(nil) = [] pi(from) = [1] The next rules are strictly ordered: p6 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: first#(s(X),cons(Y,Z)) -> activate#(Z) p2: activate#(n__s(X)) -> activate#(X) p3: activate#(n__from(X)) -> activate#(X) p4: activate#(n__first(X1,X2)) -> activate#(X2) p5: activate#(n__first(X1,X2)) -> activate#(X1) and R consists of: r1: first(|0|(),X) -> nil() r2: first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) r3: from(X) -> cons(X,n__from(n__s(X))) r4: first(X1,X2) -> n__first(X1,X2) r5: from(X) -> n__from(X) r6: s(X) -> n__s(X) r7: activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) r8: activate(n__from(X)) -> from(activate(X)) r9: activate(n__s(X)) -> s(activate(X)) r10: activate(X) -> X The estimated dependency graph contains the following SCCs: {p2, p3, p4, p5} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: activate#(n__s(X)) -> activate#(X) p2: activate#(n__first(X1,X2)) -> activate#(X1) p3: activate#(n__first(X1,X2)) -> activate#(X2) p4: activate#(n__from(X)) -> activate#(X) and R consists of: r1: first(|0|(),X) -> nil() r2: first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) r3: from(X) -> cons(X,n__from(n__s(X))) r4: first(X1,X2) -> n__first(X1,X2) r5: from(X) -> n__from(X) r6: s(X) -> n__s(X) r7: activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) r8: activate(n__from(X)) -> from(activate(X)) r9: activate(n__s(X)) -> s(activate(X)) r10: activate(X) -> X The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: activate#_A(x1) = ((1,0),(0,0)) x1 + (2,2) n__s_A(x1) = ((1,0),(0,0)) x1 + (1,3) n__first_A(x1,x2) = ((1,0),(0,0)) x1 + x2 + (3,1) n__from_A(x1) = ((1,0),(0,0)) x1 + (3,3) precedence: activate# = n__s = n__first = n__from partial status: pi(activate#) = [] pi(n__s) = [] pi(n__first) = [2] pi(n__from) = [] The next rules are strictly ordered: p2 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: activate#(n__s(X)) -> activate#(X) p2: activate#(n__first(X1,X2)) -> activate#(X2) p3: activate#(n__from(X)) -> activate#(X) and R consists of: r1: first(|0|(),X) -> nil() r2: first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) r3: from(X) -> cons(X,n__from(n__s(X))) r4: first(X1,X2) -> n__first(X1,X2) r5: from(X) -> n__from(X) r6: s(X) -> n__s(X) r7: activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) r8: activate(n__from(X)) -> from(activate(X)) r9: activate(n__s(X)) -> s(activate(X)) r10: activate(X) -> X The estimated dependency graph contains the following SCCs: {p1, p2, p3} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: activate#(n__s(X)) -> activate#(X) p2: activate#(n__from(X)) -> activate#(X) p3: activate#(n__first(X1,X2)) -> activate#(X2) and R consists of: r1: first(|0|(),X) -> nil() r2: first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) r3: from(X) -> cons(X,n__from(n__s(X))) r4: first(X1,X2) -> n__first(X1,X2) r5: from(X) -> n__from(X) r6: s(X) -> n__s(X) r7: activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) r8: activate(n__from(X)) -> from(activate(X)) r9: activate(n__s(X)) -> s(activate(X)) r10: activate(X) -> X The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: activate#_A(x1) = x1 + (1,2) n__s_A(x1) = ((1,0),(1,1)) x1 + (2,3) n__from_A(x1) = x1 + (2,1) n__first_A(x1,x2) = x1 + ((1,0),(1,1)) x2 + (2,3) precedence: n__s > n__from > activate# = n__first partial status: pi(activate#) = [1] pi(n__s) = [] pi(n__from) = [1] pi(n__first) = [1] The next rules are strictly ordered: p2 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: activate#(n__s(X)) -> activate#(X) p2: activate#(n__first(X1,X2)) -> activate#(X2) and R consists of: r1: first(|0|(),X) -> nil() r2: first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) r3: from(X) -> cons(X,n__from(n__s(X))) r4: first(X1,X2) -> n__first(X1,X2) r5: from(X) -> n__from(X) r6: s(X) -> n__s(X) r7: activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) r8: activate(n__from(X)) -> from(activate(X)) r9: activate(n__s(X)) -> s(activate(X)) r10: activate(X) -> X The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: activate#(n__s(X)) -> activate#(X) p2: activate#(n__first(X1,X2)) -> activate#(X2) and R consists of: r1: first(|0|(),X) -> nil() r2: first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) r3: from(X) -> cons(X,n__from(n__s(X))) r4: first(X1,X2) -> n__first(X1,X2) r5: from(X) -> n__from(X) r6: s(X) -> n__s(X) r7: activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) r8: activate(n__from(X)) -> from(activate(X)) r9: activate(n__s(X)) -> s(activate(X)) r10: activate(X) -> X The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: activate#_A(x1) = ((1,0),(1,0)) x1 + (1,2) n__s_A(x1) = ((1,0),(0,0)) x1 + (2,1) n__first_A(x1,x2) = x1 + ((1,0),(0,0)) x2 + (2,1) precedence: activate# = n__s = n__first partial status: pi(activate#) = [] pi(n__s) = [] pi(n__first) = [1] The next rules are strictly ordered: p1 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: activate#(n__first(X1,X2)) -> activate#(X2) and R consists of: r1: first(|0|(),X) -> nil() r2: first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) r3: from(X) -> cons(X,n__from(n__s(X))) r4: first(X1,X2) -> n__first(X1,X2) r5: from(X) -> n__from(X) r6: s(X) -> n__s(X) r7: activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) r8: activate(n__from(X)) -> from(activate(X)) r9: activate(n__s(X)) -> s(activate(X)) r10: activate(X) -> X The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: activate#(n__first(X1,X2)) -> activate#(X2) and R consists of: r1: first(|0|(),X) -> nil() r2: first(s(X),cons(Y,Z)) -> cons(Y,n__first(X,activate(Z))) r3: from(X) -> cons(X,n__from(n__s(X))) r4: first(X1,X2) -> n__first(X1,X2) r5: from(X) -> n__from(X) r6: s(X) -> n__s(X) r7: activate(n__first(X1,X2)) -> first(activate(X1),activate(X2)) r8: activate(n__from(X)) -> from(activate(X)) r9: activate(n__s(X)) -> s(activate(X)) r10: activate(X) -> X The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: activate#_A(x1) = ((1,0),(1,1)) x1 n__first_A(x1,x2) = x1 + ((1,0),(1,1)) x2 + (1,1) precedence: activate# = n__first partial status: pi(activate#) = [1] pi(n__first) = [2] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.