YES We show the termination of the TRS R: f(|0|()) -> true() f(|1|()) -> false() f(s(x)) -> f(x) if(true(),s(x),s(y)) -> s(x) if(false(),s(x),s(y)) -> s(y) g(x,c(y)) -> c(g(x,y)) g(x,c(y)) -> g(x,if(f(x),c(g(s(x),y)),c(y))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f#(s(x)) -> f#(x) p2: g#(x,c(y)) -> g#(x,y) p3: g#(x,c(y)) -> g#(x,if(f(x),c(g(s(x),y)),c(y))) p4: g#(x,c(y)) -> if#(f(x),c(g(s(x),y)),c(y)) p5: g#(x,c(y)) -> f#(x) p6: g#(x,c(y)) -> g#(s(x),y) and R consists of: r1: f(|0|()) -> true() r2: f(|1|()) -> false() r3: f(s(x)) -> f(x) r4: if(true(),s(x),s(y)) -> s(x) r5: if(false(),s(x),s(y)) -> s(y) r6: g(x,c(y)) -> c(g(x,y)) r7: g(x,c(y)) -> g(x,if(f(x),c(g(s(x),y)),c(y))) The estimated dependency graph contains the following SCCs: {p2, p6} {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: g#(x,c(y)) -> g#(s(x),y) p2: g#(x,c(y)) -> g#(x,y) and R consists of: r1: f(|0|()) -> true() r2: f(|1|()) -> false() r3: f(s(x)) -> f(x) r4: if(true(),s(x),s(y)) -> s(x) r5: if(false(),s(x),s(y)) -> s(y) r6: g(x,c(y)) -> c(g(x,y)) r7: g(x,c(y)) -> g(x,if(f(x),c(g(s(x),y)),c(y))) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: g#_A(x1,x2) = max{0, x1 - 29, x2 - 17} c_A(x1) = max{15, x1 + 4} s_A(x1) = max{28, x1 - 2} g#!_A(x1,x2) = max{5, x2 - 9} c!_A(x1) = x1 + 6 s!_A(x1) = 3 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: g#_A(x1,x2) = x1 + x2 c_A(x1) = x1 + 1 s_A(x1) = x1 + 1 g#!_A(x1,x2) = 7 c!_A(x1) = 9 s!_A(x1) = 6 partial status: pi(g#) = [1] pi(c) = [] pi(s) = [] The following rules are removed: p1, p2 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(s(x)) -> f#(x) and R consists of: r1: f(|0|()) -> true() r2: f(|1|()) -> false() r3: f(s(x)) -> f(x) r4: if(true(),s(x),s(y)) -> s(x) r5: if(false(),s(x),s(y)) -> s(y) r6: g(x,c(y)) -> c(g(x,y)) r7: g(x,c(y)) -> g(x,if(f(x),c(g(s(x),y)),c(y))) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: f#_A(x1) = 0 s_A(x1) = 20 f#!_A(x1) = 0 s!_A(x1) = max{23, x1 - 22} 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: f#_A(x1) = x1 s_A(x1) = x1 + 2 f#!_A(x1) = x1 + 3 s!_A(x1) = 4 partial status: pi(f#) = [1] pi(s) = [1] The following rules are removed: p1 Then no dependency pair remains.