YES We show the termination of the TRS R: active(f(x)) -> mark(x) top(active(c())) -> top(mark(c())) top(mark(x)) -> top(check(x)) check(f(x)) -> f(check(x)) check(x) -> start(match(f(X()),x)) match(f(x),f(y)) -> f(match(x,y)) match(X(),x) -> proper(x) proper(c()) -> ok(c()) proper(f(x)) -> f(proper(x)) f(ok(x)) -> ok(f(x)) start(ok(x)) -> found(x) f(found(x)) -> found(f(x)) top(found(x)) -> top(active(x)) active(f(x)) -> f(active(x)) f(mark(x)) -> mark(f(x)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: top#(active(c())) -> top#(mark(c())) p2: top#(mark(x)) -> top#(check(x)) p3: top#(mark(x)) -> check#(x) p4: check#(f(x)) -> f#(check(x)) p5: check#(f(x)) -> check#(x) p6: check#(x) -> start#(match(f(X()),x)) p7: check#(x) -> match#(f(X()),x) p8: check#(x) -> f#(X()) p9: match#(f(x),f(y)) -> f#(match(x,y)) p10: match#(f(x),f(y)) -> match#(x,y) p11: match#(X(),x) -> proper#(x) p12: proper#(f(x)) -> f#(proper(x)) p13: proper#(f(x)) -> proper#(x) p14: f#(ok(x)) -> f#(x) p15: f#(found(x)) -> f#(x) p16: top#(found(x)) -> top#(active(x)) p17: top#(found(x)) -> active#(x) p18: active#(f(x)) -> f#(active(x)) p19: active#(f(x)) -> active#(x) p20: f#(mark(x)) -> f#(x) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(x)) The estimated dependency graph contains the following SCCs: {p1, p2, p16} {p5} {p19} {p10} {p13} {p14, p15, p20} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: top#(active(c())) -> top#(mark(c())) p2: top#(mark(x)) -> top#(check(x)) p3: top#(found(x)) -> top#(active(x)) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(x)) The set of usable rules consists of r1, r4, r5, r6, r7, r8, r9, r10, r11, r12, r14, r15 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: top#_A(x1) = 0 active_A(x1) = x1 c_A() = 7 mark_A(x1) = 4 check_A(x1) = x1 found_A(x1) = 6 f_A(x1) = 7 start_A(x1) = x1 match_A(x1,x2) = x2 X_A() = 14 proper_A(x1) = x1 ok_A(x1) = 7 top#!_A(x1) = 0 active!_A(x1) = x1 + 3 c!_A() = 8 mark!_A(x1) = 9 check!_A(x1) = 8 found!_A(x1) = x1 + 4 f!_A(x1) = x1 + 6 start!_A(x1) = 0 match!_A(x1,x2) = x1 X!_A() = 14 proper!_A(x1) = 13 ok!_A(x1) = x1 + 5 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: top#_A(x1) = max{0, x1 - 35} active_A(x1) = max{29, x1 - 9} c_A = 40 mark_A(x1) = 5 check_A(x1) = 8 found_A(x1) = max{5, x1 - 7} f_A(x1) = 6 start_A(x1) = max{8, x1 - 2} match_A(x1,x2) = x1 + 4 X_A = 45 proper_A(x1) = 48 ok_A(x1) = max{1, x1} top#!_A(x1) = max{21, x1 - 9} active!_A(x1) = 18 c!_A = 18 mark!_A(x1) = 17 check!_A(x1) = 12 found!_A(x1) = 19 f!_A(x1) = 21 start!_A(x1) = max{20, x1 - 11} match!_A(x1,x2) = max{0, x1 - 7} X!_A = 13 proper!_A(x1) = 36 ok!_A(x1) = max{20, x1 - 5} partial status: pi(top#) = [] pi(active) = [1] pi(c) = [] pi(mark) = [] pi(check) = [1] pi(found) = [] pi(f) = [] pi(start) = [1] pi(match) = [2] pi(X) = [] pi(proper) = [1] pi(ok) = [] The following rules are removed: p1 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: top#(mark(x)) -> top#(check(x)) p2: top#(found(x)) -> top#(active(x)) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(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: top#(mark(x)) -> top#(check(x)) p2: top#(found(x)) -> top#(active(x)) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(x)) The set of usable rules consists of r1, r4, r5, r6, r7, r8, r9, r10, r11, r12, r14, r15 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: top#_A(x1) = 0 mark_A(x1) = x1 check_A(x1) = x1 found_A(x1) = 2 active_A(x1) = x1 f_A(x1) = x1 + 1 start_A(x1) = x1 match_A(x1,x2) = x2 X_A() = 0 proper_A(x1) = x1 c_A() = 7 ok_A(x1) = 7 top#!_A(x1) = 4 mark!_A(x1) = x1 + 5 check!_A(x1) = x1 + 3 found!_A(x1) = 8 active!_A(x1) = x1 + 9 f!_A(x1) = x1 + 7 start!_A(x1) = x1 + 2 match!_A(x1,x2) = 2 X!_A() = 0 proper!_A(x1) = 1 c!_A() = 17 ok!_A(x1) = 13 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: top#_A(x1) = 0 mark_A(x1) = x1 + 15 check_A(x1) = x1 + 13 found_A(x1) = max{10, x1 + 9} active_A(x1) = x1 + 9 f_A(x1) = x1 + 18 start_A(x1) = max{10, x1 - 7} match_A(x1,x2) = x2 + 20 X_A = 19 proper_A(x1) = x1 + 20 c_A = 5 ok_A(x1) = x1 + 16 top#!_A(x1) = max{0, x1 - 3} mark!_A(x1) = 0 check!_A(x1) = 13 found!_A(x1) = 7 active!_A(x1) = max{0, x1 - 19} f!_A(x1) = 14 start!_A(x1) = 8 match!_A(x1,x2) = max{12, x1 - 37} X!_A = 1 proper!_A(x1) = 2 c!_A = 3 ok!_A(x1) = max{0, x1 - 6} partial status: pi(top#) = [] pi(mark) = [] pi(check) = [1] pi(found) = [] pi(active) = [1] pi(f) = [] pi(start) = [] pi(match) = [2] pi(X) = [] pi(proper) = [1] pi(c) = [] pi(ok) = [] The following rules are removed: p1 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: top#(found(x)) -> top#(active(x)) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(x)) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: top#(found(x)) -> top#(active(x)) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(x)) The set of usable rules consists of r1, r10, r12, r14, r15 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: top#_A(x1) = 0 found_A(x1) = 3 active_A(x1) = x1 f_A(x1) = 3 mark_A(x1) = 0 ok_A(x1) = 3 top#!_A(x1) = 11 found!_A(x1) = x1 + 9 active!_A(x1) = x1 + 10 f!_A(x1) = x1 + 9 mark!_A(x1) = x1 + 5 ok!_A(x1) = 8 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: top#_A(x1) = 0 found_A(x1) = 12 active_A(x1) = 9 f_A(x1) = max{9, x1} mark_A(x1) = 1 ok_A(x1) = max{5, x1 - 2} top#!_A(x1) = max{1, x1 - 10} found!_A(x1) = 2 active!_A(x1) = x1 f!_A(x1) = 2 mark!_A(x1) = max{13, x1 + 3} ok!_A(x1) = 0 partial status: pi(top#) = [] pi(found) = [] pi(active) = [1] pi(f) = [] pi(mark) = [] pi(ok) = [] The following rules are removed: p1 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: check#(f(x)) -> check#(x) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(x)) 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: check#_A(x1) = x1 f_A(x1) = x1 + 4 check#!_A(x1) = 0 f!_A(x1) = 10 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: check#_A(x1) = 0 f_A(x1) = max{35, x1 + 12} check#!_A(x1) = max{1, x1 - 6} f!_A(x1) = max{3, x1 - 5} partial status: pi(check#) = [] pi(f) = [] The following rules are removed: p1 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: active#(f(x)) -> active#(x) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(x)) 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: active#_A(x1) = x1 f_A(x1) = x1 + 3 active#!_A(x1) = x1 f!_A(x1) = 4 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: active#_A(x1) = 0 f_A(x1) = max{37, x1 - 24} active#!_A(x1) = max{32, x1 - 38} f!_A(x1) = max{31, x1 + 24} partial status: pi(active#) = [] pi(f) = [1] The following rules are removed: p1 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: match#(f(x),f(y)) -> match#(x,y) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(x)) 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: match#_A(x1,x2) = x1 + x2 f_A(x1) = x1 + 7 match#!_A(x1,x2) = 5 f!_A(x1) = x1 + 5 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: match#_A(x1,x2) = 0 f_A(x1) = 6 match#!_A(x1,x2) = 1 f!_A(x1) = 9 partial status: pi(match#) = [1] pi(f) = [1] The following rules are removed: p1 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: proper#(f(x)) -> proper#(x) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(x)) 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: proper#_A(x1) = x1 f_A(x1) = x1 + 4 proper#!_A(x1) = x1 + 4 f!_A(x1) = 3 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: proper#_A(x1) = 0 f_A(x1) = max{31, x1 - 50} proper#!_A(x1) = max{27, x1 - 32} f!_A(x1) = x1 + 26 partial status: pi(proper#) = [] pi(f) = [] The following rules are removed: p1 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(ok(x)) -> f#(x) p2: f#(mark(x)) -> f#(x) p3: f#(found(x)) -> f#(x) and R consists of: r1: active(f(x)) -> mark(x) r2: top(active(c())) -> top(mark(c())) r3: top(mark(x)) -> top(check(x)) r4: check(f(x)) -> f(check(x)) r5: check(x) -> start(match(f(X()),x)) r6: match(f(x),f(y)) -> f(match(x,y)) r7: match(X(),x) -> proper(x) r8: proper(c()) -> ok(c()) r9: proper(f(x)) -> f(proper(x)) r10: f(ok(x)) -> ok(f(x)) r11: start(ok(x)) -> found(x) r12: f(found(x)) -> found(f(x)) r13: top(found(x)) -> top(active(x)) r14: active(f(x)) -> f(active(x)) r15: f(mark(x)) -> mark(f(x)) 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: f#_A(x1) = x1 ok_A(x1) = x1 + 1 mark_A(x1) = x1 + 8 found_A(x1) = x1 + 3 f#!_A(x1) = x1 + 3 ok!_A(x1) = 7 mark!_A(x1) = 4 found!_A(x1) = 7 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: f#_A(x1) = 0 ok_A(x1) = max{9, x1 - 25} mark_A(x1) = max{9, x1 - 9} found_A(x1) = max{9, x1 - 23} f#!_A(x1) = max{4, x1 - 34} ok!_A(x1) = max{3, x1 - 35} mark!_A(x1) = 0 found!_A(x1) = max{3, x1 - 35} partial status: pi(f#) = [] pi(ok) = [1] pi(mark) = [] pi(found) = [1] The following rules are removed: p1, p2, p3 Then no dependency pair remains.