YES We show the termination of the TRS R: active(f(a(),X,X)) -> mark(f(X,b(),b())) active(b()) -> mark(a()) mark(f(X1,X2,X3)) -> active(f(X1,mark(X2),X3)) mark(a()) -> active(a()) mark(b()) -> active(b()) f(mark(X1),X2,X3) -> f(X1,X2,X3) f(X1,mark(X2),X3) -> f(X1,X2,X3) f(X1,X2,mark(X3)) -> f(X1,X2,X3) f(active(X1),X2,X3) -> f(X1,X2,X3) f(X1,active(X2),X3) -> f(X1,X2,X3) f(X1,X2,active(X3)) -> f(X1,X2,X3) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: active#(f(a(),X,X)) -> mark#(f(X,b(),b())) p2: active#(f(a(),X,X)) -> f#(X,b(),b()) p3: active#(b()) -> mark#(a()) p4: mark#(f(X1,X2,X3)) -> active#(f(X1,mark(X2),X3)) p5: mark#(f(X1,X2,X3)) -> f#(X1,mark(X2),X3) p6: mark#(f(X1,X2,X3)) -> mark#(X2) p7: mark#(a()) -> active#(a()) p8: mark#(b()) -> active#(b()) p9: f#(mark(X1),X2,X3) -> f#(X1,X2,X3) p10: f#(X1,mark(X2),X3) -> f#(X1,X2,X3) p11: f#(X1,X2,mark(X3)) -> f#(X1,X2,X3) p12: f#(active(X1),X2,X3) -> f#(X1,X2,X3) p13: f#(X1,active(X2),X3) -> f#(X1,X2,X3) p14: f#(X1,X2,active(X3)) -> f#(X1,X2,X3) and R consists of: r1: active(f(a(),X,X)) -> mark(f(X,b(),b())) r2: active(b()) -> mark(a()) r3: mark(f(X1,X2,X3)) -> active(f(X1,mark(X2),X3)) r4: mark(a()) -> active(a()) r5: mark(b()) -> active(b()) r6: f(mark(X1),X2,X3) -> f(X1,X2,X3) r7: f(X1,mark(X2),X3) -> f(X1,X2,X3) r8: f(X1,X2,mark(X3)) -> f(X1,X2,X3) r9: f(active(X1),X2,X3) -> f(X1,X2,X3) r10: f(X1,active(X2),X3) -> f(X1,X2,X3) r11: f(X1,X2,active(X3)) -> f(X1,X2,X3) The estimated dependency graph contains the following SCCs: {p1, p4, p6} {p9, p10, p11, p12, p13, p14} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: active#(f(a(),X,X)) -> mark#(f(X,b(),b())) p2: mark#(f(X1,X2,X3)) -> mark#(X2) p3: mark#(f(X1,X2,X3)) -> active#(f(X1,mark(X2),X3)) and R consists of: r1: active(f(a(),X,X)) -> mark(f(X,b(),b())) r2: active(b()) -> mark(a()) r3: mark(f(X1,X2,X3)) -> active(f(X1,mark(X2),X3)) r4: mark(a()) -> active(a()) r5: mark(b()) -> active(b()) r6: f(mark(X1),X2,X3) -> f(X1,X2,X3) r7: f(X1,mark(X2),X3) -> f(X1,X2,X3) r8: f(X1,X2,mark(X3)) -> f(X1,X2,X3) r9: f(active(X1),X2,X3) -> f(X1,X2,X3) r10: f(X1,active(X2),X3) -> f(X1,X2,X3) r11: f(X1,X2,active(X3)) -> f(X1,X2,X3) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: active#_A(x1) = max{23, x1 + 11} f_A(x1,x2,x3) = max{x1 - 1, x2 + 9, x3 + 5} a_A = 0 mark#_A(x1) = x1 + 14 b_A = 0 mark_A(x1) = x1 active_A(x1) = x1 precedence: active# = f = mark# = b > mark = active > a partial status: pi(active#) = [1] pi(f) = [] pi(a) = [] pi(mark#) = [1] pi(b) = [] pi(mark) = [1] pi(active) = [1] 2. weighted path order base order: max/plus interpretations on natural numbers: active#_A(x1) = 29 f_A(x1,x2,x3) = 28 a_A = 9 mark#_A(x1) = max{29, x1 - 28} b_A = 11 mark_A(x1) = 10 active_A(x1) = 10 precedence: f > active# = a = mark# = b > mark = active partial status: pi(active#) = [] pi(f) = [] pi(a) = [] pi(mark#) = [] pi(b) = [] pi(mark) = [] pi(active) = [] 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: active#(f(a(),X,X)) -> mark#(f(X,b(),b())) p2: mark#(f(X1,X2,X3)) -> active#(f(X1,mark(X2),X3)) and R consists of: r1: active(f(a(),X,X)) -> mark(f(X,b(),b())) r2: active(b()) -> mark(a()) r3: mark(f(X1,X2,X3)) -> active(f(X1,mark(X2),X3)) r4: mark(a()) -> active(a()) r5: mark(b()) -> active(b()) r6: f(mark(X1),X2,X3) -> f(X1,X2,X3) r7: f(X1,mark(X2),X3) -> f(X1,X2,X3) r8: f(X1,X2,mark(X3)) -> f(X1,X2,X3) r9: f(active(X1),X2,X3) -> f(X1,X2,X3) r10: f(X1,active(X2),X3) -> f(X1,X2,X3) r11: f(X1,X2,active(X3)) -> f(X1,X2,X3) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: active#(f(a(),X,X)) -> mark#(f(X,b(),b())) p2: mark#(f(X1,X2,X3)) -> active#(f(X1,mark(X2),X3)) and R consists of: r1: active(f(a(),X,X)) -> mark(f(X,b(),b())) r2: active(b()) -> mark(a()) r3: mark(f(X1,X2,X3)) -> active(f(X1,mark(X2),X3)) r4: mark(a()) -> active(a()) r5: mark(b()) -> active(b()) r6: f(mark(X1),X2,X3) -> f(X1,X2,X3) r7: f(X1,mark(X2),X3) -> f(X1,X2,X3) r8: f(X1,X2,mark(X3)) -> f(X1,X2,X3) r9: f(active(X1),X2,X3) -> f(X1,X2,X3) r10: f(X1,active(X2),X3) -> f(X1,X2,X3) r11: f(X1,X2,active(X3)) -> f(X1,X2,X3) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: active#_A(x1) = max{26, x1 + 25} f_A(x1,x2,x3) = max{x1 + 39, x3 + 48} a_A = 19 mark#_A(x1) = x1 + 32 b_A = 1 mark_A(x1) = max{28, x1 + 8} active_A(x1) = max{28, x1} precedence: mark = active > active# = a = mark# > b > f partial status: pi(active#) = [1] pi(f) = [1] pi(a) = [] pi(mark#) = [] pi(b) = [] pi(mark) = [] pi(active) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: active#_A(x1) = 11 f_A(x1,x2,x3) = 15 a_A = 6 mark#_A(x1) = 0 b_A = 10 mark_A(x1) = 2 active_A(x1) = 2 precedence: f > active# = a = mark# = b = mark = active partial status: pi(active#) = [] pi(f) = [] pi(a) = [] pi(mark#) = [] pi(b) = [] pi(mark) = [] pi(active) = [] 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: active#(f(a(),X,X)) -> mark#(f(X,b(),b())) and R consists of: r1: active(f(a(),X,X)) -> mark(f(X,b(),b())) r2: active(b()) -> mark(a()) r3: mark(f(X1,X2,X3)) -> active(f(X1,mark(X2),X3)) r4: mark(a()) -> active(a()) r5: mark(b()) -> active(b()) r6: f(mark(X1),X2,X3) -> f(X1,X2,X3) r7: f(X1,mark(X2),X3) -> f(X1,X2,X3) r8: f(X1,X2,mark(X3)) -> f(X1,X2,X3) r9: f(active(X1),X2,X3) -> f(X1,X2,X3) r10: f(X1,active(X2),X3) -> f(X1,X2,X3) r11: f(X1,X2,active(X3)) -> f(X1,X2,X3) The estimated dependency graph contains the following SCCs: (no SCCs) -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(mark(X1),X2,X3) -> f#(X1,X2,X3) p2: f#(X1,X2,active(X3)) -> f#(X1,X2,X3) p3: f#(X1,active(X2),X3) -> f#(X1,X2,X3) p4: f#(active(X1),X2,X3) -> f#(X1,X2,X3) p5: f#(X1,X2,mark(X3)) -> f#(X1,X2,X3) p6: f#(X1,mark(X2),X3) -> f#(X1,X2,X3) and R consists of: r1: active(f(a(),X,X)) -> mark(f(X,b(),b())) r2: active(b()) -> mark(a()) r3: mark(f(X1,X2,X3)) -> active(f(X1,mark(X2),X3)) r4: mark(a()) -> active(a()) r5: mark(b()) -> active(b()) r6: f(mark(X1),X2,X3) -> f(X1,X2,X3) r7: f(X1,mark(X2),X3) -> f(X1,X2,X3) r8: f(X1,X2,mark(X3)) -> f(X1,X2,X3) r9: f(active(X1),X2,X3) -> f(X1,X2,X3) r10: f(X1,active(X2),X3) -> f(X1,X2,X3) r11: f(X1,X2,active(X3)) -> f(X1,X2,X3) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: f#_A(x1,x2,x3) = max{3, x1 + 1, x2 + 1, x3 + 1} mark_A(x1) = max{2, x1 + 1} active_A(x1) = max{1, x1} precedence: f# = mark = active partial status: pi(f#) = [1, 2] pi(mark) = [1] pi(active) = [1] 2. weighted path order base order: max/plus interpretations on natural numbers: f#_A(x1,x2,x3) = max{2, x1 + 1, x2 + 1} mark_A(x1) = max{1, x1} active_A(x1) = x1 + 1 precedence: f# = mark = active partial status: pi(f#) = [1, 2] pi(mark) = [1] pi(active) = [] The next rules are strictly ordered: p1, p3, p4, p6 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f#(X1,X2,active(X3)) -> f#(X1,X2,X3) p2: f#(X1,X2,mark(X3)) -> f#(X1,X2,X3) and R consists of: r1: active(f(a(),X,X)) -> mark(f(X,b(),b())) r2: active(b()) -> mark(a()) r3: mark(f(X1,X2,X3)) -> active(f(X1,mark(X2),X3)) r4: mark(a()) -> active(a()) r5: mark(b()) -> active(b()) r6: f(mark(X1),X2,X3) -> f(X1,X2,X3) r7: f(X1,mark(X2),X3) -> f(X1,X2,X3) r8: f(X1,X2,mark(X3)) -> f(X1,X2,X3) r9: f(active(X1),X2,X3) -> f(X1,X2,X3) r10: f(X1,active(X2),X3) -> f(X1,X2,X3) r11: f(X1,X2,active(X3)) -> f(X1,X2,X3) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(X1,X2,active(X3)) -> f#(X1,X2,X3) p2: f#(X1,X2,mark(X3)) -> f#(X1,X2,X3) and R consists of: r1: active(f(a(),X,X)) -> mark(f(X,b(),b())) r2: active(b()) -> mark(a()) r3: mark(f(X1,X2,X3)) -> active(f(X1,mark(X2),X3)) r4: mark(a()) -> active(a()) r5: mark(b()) -> active(b()) r6: f(mark(X1),X2,X3) -> f(X1,X2,X3) r7: f(X1,mark(X2),X3) -> f(X1,X2,X3) r8: f(X1,X2,mark(X3)) -> f(X1,X2,X3) r9: f(active(X1),X2,X3) -> f(X1,X2,X3) r10: f(X1,active(X2),X3) -> f(X1,X2,X3) r11: f(X1,X2,active(X3)) -> f(X1,X2,X3) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: f#_A(x1,x2,x3) = max{2, x1, x2 + 1, x3 + 1} active_A(x1) = max{1, x1} mark_A(x1) = max{1, x1} precedence: f# = active = mark partial status: pi(f#) = [1, 3] pi(active) = [1] pi(mark) = [1] 2. weighted path order base order: max/plus interpretations on natural numbers: f#_A(x1,x2,x3) = max{0, x3 - 2} active_A(x1) = max{3, x1 + 1} mark_A(x1) = x1 precedence: f# = active = mark partial status: pi(f#) = [] pi(active) = [1] pi(mark) = [1] The next rules are strictly ordered: p1, p2 We remove them from the problem. Then no dependency pair remains.