YES We show the termination of the TRS R: active(f(x)) -> mark(f(f(x))) chk(no(f(x))) -> f(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) mat(f(x),f(y())) -> f(mat(x,y())) chk(no(c())) -> active(c()) mat(f(x),c()) -> no(c()) f(active(x)) -> active(f(x)) f(no(x)) -> no(f(x)) f(mark(x)) -> mark(f(x)) tp(mark(x)) -> tp(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: active#(f(x)) -> f#(f(x)) p2: chk#(no(f(x))) -> f#(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) p3: chk#(no(f(x))) -> chk#(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x)) p4: chk#(no(f(x))) -> mat#(f(f(f(f(f(f(f(f(f(f(X())))))))))),x) p5: chk#(no(f(x))) -> f#(f(f(f(f(f(f(f(f(f(X())))))))))) p6: chk#(no(f(x))) -> f#(f(f(f(f(f(f(f(f(X()))))))))) p7: chk#(no(f(x))) -> f#(f(f(f(f(f(f(f(X())))))))) p8: chk#(no(f(x))) -> f#(f(f(f(f(f(f(X()))))))) p9: chk#(no(f(x))) -> f#(f(f(f(f(f(X())))))) p10: chk#(no(f(x))) -> f#(f(f(f(f(X()))))) p11: chk#(no(f(x))) -> f#(f(f(f(X())))) p12: chk#(no(f(x))) -> f#(f(f(X()))) p13: chk#(no(f(x))) -> f#(f(X())) p14: chk#(no(f(x))) -> f#(X()) p15: mat#(f(x),f(y())) -> f#(mat(x,y())) p16: mat#(f(x),f(y())) -> mat#(x,y()) p17: chk#(no(c())) -> active#(c()) p18: f#(active(x)) -> active#(f(x)) p19: f#(active(x)) -> f#(x) p20: f#(no(x)) -> f#(x) p21: f#(mark(x)) -> f#(x) p22: tp#(mark(x)) -> tp#(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) p23: tp#(mark(x)) -> chk#(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x)) p24: tp#(mark(x)) -> mat#(f(f(f(f(f(f(f(f(f(f(X())))))))))),x) p25: tp#(mark(x)) -> f#(f(f(f(f(f(f(f(f(f(X())))))))))) p26: tp#(mark(x)) -> f#(f(f(f(f(f(f(f(f(X()))))))))) p27: tp#(mark(x)) -> f#(f(f(f(f(f(f(f(X())))))))) p28: tp#(mark(x)) -> f#(f(f(f(f(f(f(X()))))))) p29: tp#(mark(x)) -> f#(f(f(f(f(f(X())))))) p30: tp#(mark(x)) -> f#(f(f(f(f(X()))))) p31: tp#(mark(x)) -> f#(f(f(f(X())))) p32: tp#(mark(x)) -> f#(f(f(X()))) p33: tp#(mark(x)) -> f#(f(X())) p34: tp#(mark(x)) -> f#(X()) and R consists of: r1: active(f(x)) -> mark(f(f(x))) r2: chk(no(f(x))) -> f(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) r3: mat(f(x),f(y())) -> f(mat(x,y())) r4: chk(no(c())) -> active(c()) r5: mat(f(x),c()) -> no(c()) r6: f(active(x)) -> active(f(x)) r7: f(no(x)) -> no(f(x)) r8: f(mark(x)) -> mark(f(x)) r9: tp(mark(x)) -> tp(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) The estimated dependency graph contains the following SCCs: {p22} {p3} {p1, p18, p19, p20, p21} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: tp#(mark(x)) -> tp#(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) and R consists of: r1: active(f(x)) -> mark(f(f(x))) r2: chk(no(f(x))) -> f(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) r3: mat(f(x),f(y())) -> f(mat(x,y())) r4: chk(no(c())) -> active(c()) r5: mat(f(x),c()) -> no(c()) r6: f(active(x)) -> active(f(x)) r7: f(no(x)) -> no(f(x)) r8: f(mark(x)) -> mark(f(x)) r9: tp(mark(x)) -> tp(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8 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: tp#_A(x1) = 0 mark_A(x1) = max{8, x1} chk_A(x1) = 18 mat_A(x1,x2) = 8 f_A(x1) = 8 X_A = 19 active_A(x1) = max{8, x1 - 1} no_A(x1) = max{8, x1 - 3} y_A = 20 c_A = 4 tp#!_A(x1) = 0 mark!_A(x1) = 20 chk!_A(x1) = max{11, x1 + 10} mat!_A(x1,x2) = max{19, x1 - 10} f!_A(x1) = max{21, x1 + 2} X!_A = 8 active!_A(x1) = x1 + 13 no!_A(x1) = x1 + 13 y!_A = 21 c!_A = 18 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: tp#_A(x1) = 0 mark_A(x1) = x1 + 1 chk_A(x1) = 3 mat_A(x1,x2) = x2 + 4 f_A(x1) = x1 X_A() = 3 active_A(x1) = x1 + 2 no_A(x1) = 5 y_A() = 1 c_A() = 1 tp#!_A(x1) = x1 + 1 mark!_A(x1) = 2 chk!_A(x1) = 1 mat!_A(x1,x2) = 1 f!_A(x1) = x1 + 3 X!_A() = 0 active!_A(x1) = x1 + 4 no!_A(x1) = 7 y!_A() = 9 c!_A() = 1 partial status: pi(tp#) = [1] pi(mark) = [1] pi(chk) = [1] pi(mat) = [2] pi(f) = [] pi(X) = [] pi(active) = [] pi(no) = [] pi(y) = [] pi(c) = [] 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: chk#(no(f(x))) -> chk#(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x)) and R consists of: r1: active(f(x)) -> mark(f(f(x))) r2: chk(no(f(x))) -> f(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) r3: mat(f(x),f(y())) -> f(mat(x,y())) r4: chk(no(c())) -> active(c()) r5: mat(f(x),c()) -> no(c()) r6: f(active(x)) -> active(f(x)) r7: f(no(x)) -> no(f(x)) r8: f(mark(x)) -> mark(f(x)) r9: tp(mark(x)) -> tp(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) The set of usable rules consists of r3, r5 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: chk#_A(x1) = 0 no_A(x1) = max{0, x1 - 435} f_A(x1) = max{21, x1 - 41} mat_A(x1,x2) = max{65, x1 - 25, x2 + 2} X_A = 507 y_A = 2 c_A = 431 chk#!_A(x1) = 3 no!_A(x1) = max{401, x1 - 28} f!_A(x1) = max{4, x1 - 26} mat!_A(x1,x2) = max{406, x1 + 114, x2 - 29} X!_A = 2 y!_A = 407 c!_A = 405 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: chk#_A(x1) = x1 no_A(x1) = x1 + 1 f_A(x1) = x1 + 4 mat_A(x1,x2) = x2 + 4 X_A() = 3 y_A() = 37 c_A() = 1 chk#!_A(x1) = x1 no!_A(x1) = 43 f!_A(x1) = x1 + 3 mat!_A(x1,x2) = 45 X!_A() = 1 y!_A() = 46 c!_A() = 44 partial status: pi(chk#) = [] pi(no) = [] pi(f) = [] pi(mat) = [2] pi(X) = [] pi(y) = [] pi(c) = [] 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)) -> f#(f(x)) p2: f#(mark(x)) -> f#(x) p3: f#(no(x)) -> f#(x) p4: f#(active(x)) -> f#(x) p5: f#(active(x)) -> active#(f(x)) and R consists of: r1: active(f(x)) -> mark(f(f(x))) r2: chk(no(f(x))) -> f(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) r3: mat(f(x),f(y())) -> f(mat(x,y())) r4: chk(no(c())) -> active(c()) r5: mat(f(x),c()) -> no(c()) r6: f(active(x)) -> active(f(x)) r7: f(no(x)) -> no(f(x)) r8: f(mark(x)) -> mark(f(x)) r9: tp(mark(x)) -> tp(chk(mat(f(f(f(f(f(f(f(f(f(f(X())))))))))),x))) The set of usable rules consists of r1, r6, r7, r8 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: active#_A(x1) = 1 f_A(x1) = max{143, x1 - 63} f#_A(x1) = 1 mark_A(x1) = max{61, x1} no_A(x1) = max{27, x1 - 55} active_A(x1) = max{143, x1} active#!_A(x1) = max{329, x1 - 141} f!_A(x1) = max{329, x1 + 56} f#!_A(x1) = max{1, x1 - 204} mark!_A(x1) = max{328, x1 - 197} no!_A(x1) = max{329, x1 + 62} active!_A(x1) = max{329, x1 + 119} 2. marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: active#_A(x1) = 0 f_A(x1) = x1 + 5 f#_A(x1) = 0 mark_A(x1) = x1 + 7 no_A(x1) = x1 + 10 active_A(x1) = x1 + 20 active#!_A(x1) = x1 + 2 f!_A(x1) = x1 + 6 f#!_A(x1) = x1 mark!_A(x1) = x1 + 7 no!_A(x1) = x1 + 10 active!_A(x1) = x1 + 20 partial status: pi(active#) = [1] pi(f) = [1] pi(f#) = [1] pi(mark) = [1] pi(no) = [1] pi(active) = [1] The following rules are removed: p1, p2, p3, p4, p5 Then no dependency pair remains.