YES We show the termination of the TRS R: active(and(true(),X)) -> mark(X) active(and(false(),Y)) -> mark(false()) active(if(true(),X,Y)) -> mark(X) active(if(false(),X,Y)) -> mark(Y) active(add(|0|(),X)) -> mark(X) active(add(s(X),Y)) -> mark(s(add(X,Y))) active(first(|0|(),X)) -> mark(nil()) active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) active(from(X)) -> mark(cons(X,from(s(X)))) mark(and(X1,X2)) -> active(and(mark(X1),X2)) mark(true()) -> active(true()) mark(false()) -> active(false()) mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) mark(add(X1,X2)) -> active(add(mark(X1),X2)) mark(|0|()) -> active(|0|()) mark(s(X)) -> active(s(X)) mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) mark(nil()) -> active(nil()) mark(cons(X1,X2)) -> active(cons(X1,X2)) mark(from(X)) -> active(from(X)) and(mark(X1),X2) -> and(X1,X2) and(X1,mark(X2)) -> and(X1,X2) and(active(X1),X2) -> and(X1,X2) and(X1,active(X2)) -> and(X1,X2) if(mark(X1),X2,X3) -> if(X1,X2,X3) if(X1,mark(X2),X3) -> if(X1,X2,X3) if(X1,X2,mark(X3)) -> if(X1,X2,X3) if(active(X1),X2,X3) -> if(X1,X2,X3) if(X1,active(X2),X3) -> if(X1,X2,X3) if(X1,X2,active(X3)) -> if(X1,X2,X3) add(mark(X1),X2) -> add(X1,X2) add(X1,mark(X2)) -> add(X1,X2) add(active(X1),X2) -> add(X1,X2) add(X1,active(X2)) -> add(X1,X2) s(mark(X)) -> s(X) s(active(X)) -> s(X) first(mark(X1),X2) -> first(X1,X2) first(X1,mark(X2)) -> first(X1,X2) first(active(X1),X2) -> first(X1,X2) first(X1,active(X2)) -> first(X1,X2) cons(mark(X1),X2) -> cons(X1,X2) cons(X1,mark(X2)) -> cons(X1,X2) cons(active(X1),X2) -> cons(X1,X2) cons(X1,active(X2)) -> cons(X1,X2) from(mark(X)) -> from(X) from(active(X)) -> from(X) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: active#(and(true(),X)) -> mark#(X) p2: active#(and(false(),Y)) -> mark#(false()) p3: active#(if(true(),X,Y)) -> mark#(X) p4: active#(if(false(),X,Y)) -> mark#(Y) p5: active#(add(|0|(),X)) -> mark#(X) p6: active#(add(s(X),Y)) -> mark#(s(add(X,Y))) p7: active#(add(s(X),Y)) -> s#(add(X,Y)) p8: active#(add(s(X),Y)) -> add#(X,Y) p9: active#(first(|0|(),X)) -> mark#(nil()) p10: active#(first(s(X),cons(Y,Z))) -> mark#(cons(Y,first(X,Z))) p11: active#(first(s(X),cons(Y,Z))) -> cons#(Y,first(X,Z)) p12: active#(first(s(X),cons(Y,Z))) -> first#(X,Z) p13: active#(from(X)) -> mark#(cons(X,from(s(X)))) p14: active#(from(X)) -> cons#(X,from(s(X))) p15: active#(from(X)) -> from#(s(X)) p16: active#(from(X)) -> s#(X) p17: mark#(and(X1,X2)) -> active#(and(mark(X1),X2)) p18: mark#(and(X1,X2)) -> and#(mark(X1),X2) p19: mark#(and(X1,X2)) -> mark#(X1) p20: mark#(true()) -> active#(true()) p21: mark#(false()) -> active#(false()) p22: mark#(if(X1,X2,X3)) -> active#(if(mark(X1),X2,X3)) p23: mark#(if(X1,X2,X3)) -> if#(mark(X1),X2,X3) p24: mark#(if(X1,X2,X3)) -> mark#(X1) p25: mark#(add(X1,X2)) -> active#(add(mark(X1),X2)) p26: mark#(add(X1,X2)) -> add#(mark(X1),X2) p27: mark#(add(X1,X2)) -> mark#(X1) p28: mark#(|0|()) -> active#(|0|()) p29: mark#(s(X)) -> active#(s(X)) p30: mark#(first(X1,X2)) -> active#(first(mark(X1),mark(X2))) p31: mark#(first(X1,X2)) -> first#(mark(X1),mark(X2)) p32: mark#(first(X1,X2)) -> mark#(X1) p33: mark#(first(X1,X2)) -> mark#(X2) p34: mark#(nil()) -> active#(nil()) p35: mark#(cons(X1,X2)) -> active#(cons(X1,X2)) p36: mark#(from(X)) -> active#(from(X)) p37: and#(mark(X1),X2) -> and#(X1,X2) p38: and#(X1,mark(X2)) -> and#(X1,X2) p39: and#(active(X1),X2) -> and#(X1,X2) p40: and#(X1,active(X2)) -> and#(X1,X2) p41: if#(mark(X1),X2,X3) -> if#(X1,X2,X3) p42: if#(X1,mark(X2),X3) -> if#(X1,X2,X3) p43: if#(X1,X2,mark(X3)) -> if#(X1,X2,X3) p44: if#(active(X1),X2,X3) -> if#(X1,X2,X3) p45: if#(X1,active(X2),X3) -> if#(X1,X2,X3) p46: if#(X1,X2,active(X3)) -> if#(X1,X2,X3) p47: add#(mark(X1),X2) -> add#(X1,X2) p48: add#(X1,mark(X2)) -> add#(X1,X2) p49: add#(active(X1),X2) -> add#(X1,X2) p50: add#(X1,active(X2)) -> add#(X1,X2) p51: s#(mark(X)) -> s#(X) p52: s#(active(X)) -> s#(X) p53: first#(mark(X1),X2) -> first#(X1,X2) p54: first#(X1,mark(X2)) -> first#(X1,X2) p55: first#(active(X1),X2) -> first#(X1,X2) p56: first#(X1,active(X2)) -> first#(X1,X2) p57: cons#(mark(X1),X2) -> cons#(X1,X2) p58: cons#(X1,mark(X2)) -> cons#(X1,X2) p59: cons#(active(X1),X2) -> cons#(X1,X2) p60: cons#(X1,active(X2)) -> cons#(X1,X2) p61: from#(mark(X)) -> from#(X) p62: from#(active(X)) -> from#(X) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The estimated dependency graph contains the following SCCs: {p1, p3, p4, p5, p6, p10, p13, p17, p19, p22, p24, p25, p27, p29, p30, p32, p33, p35, p36} {p51, p52} {p47, p48, p49, p50} {p57, p58, p59, p60} {p53, p54, p55, p56} {p61, p62} {p37, p38, p39, p40} {p41, p42, p43, p44, p45, p46} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: active#(and(true(),X)) -> mark#(X) p2: mark#(from(X)) -> active#(from(X)) p3: active#(from(X)) -> mark#(cons(X,from(s(X)))) p4: mark#(cons(X1,X2)) -> active#(cons(X1,X2)) p5: active#(first(s(X),cons(Y,Z))) -> mark#(cons(Y,first(X,Z))) p6: mark#(first(X1,X2)) -> mark#(X2) p7: mark#(first(X1,X2)) -> mark#(X1) p8: mark#(first(X1,X2)) -> active#(first(mark(X1),mark(X2))) p9: active#(add(s(X),Y)) -> mark#(s(add(X,Y))) p10: mark#(s(X)) -> active#(s(X)) p11: active#(add(|0|(),X)) -> mark#(X) p12: mark#(add(X1,X2)) -> mark#(X1) p13: mark#(add(X1,X2)) -> active#(add(mark(X1),X2)) p14: active#(if(false(),X,Y)) -> mark#(Y) p15: mark#(if(X1,X2,X3)) -> mark#(X1) p16: mark#(if(X1,X2,X3)) -> active#(if(mark(X1),X2,X3)) p17: active#(if(true(),X,Y)) -> mark#(X) p18: mark#(and(X1,X2)) -> mark#(X1) p19: mark#(and(X1,X2)) -> active#(and(mark(X1),X2)) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17, r18, r19, r20, r21, r22, r23, r24, r25, r26, r27, r28, r29, r30, r31, r32, r33, r34, r35, r36, r37, r38, r39, r40, r41, r42, r43, r44, r45, r46 Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order precedence: |0| > nil > false > if > and > s > add > first > from > mark > active > true > mark# > active# > cons argument filter: pi(active#) = 1 pi(and) = [1, 2] pi(true) = [] pi(mark#) = [1] pi(from) = [1] pi(cons) = 1 pi(s) = [] pi(first) = [1, 2] pi(mark) = 1 pi(add) = [1, 2] pi(|0|) = [] pi(if) = [1, 2, 3] pi(false) = [] pi(active) = 1 pi(nil) = [] 2. lexicographic path order precedence: nil > mark# > false > active# > s > mark > |0| > add > first > cons > from > and > active > if > true argument filter: pi(active#) = [1] pi(and) = [1] pi(true) = [] pi(mark#) = [1] pi(from) = 1 pi(cons) = [1] pi(s) = [] pi(first) = [1, 2] pi(mark) = [1] pi(add) = 2 pi(|0|) = [] pi(if) = [1, 3] pi(false) = [] pi(active) = [1] pi(nil) = [] 3. lexicographic path order precedence: nil > mark > active > active# > from > s > add > mark# > false > if > |0| > cons > first > true > and argument filter: pi(active#) = [1] pi(and) = 1 pi(true) = [] pi(mark#) = [1] pi(from) = [1] pi(cons) = [1] pi(s) = [] pi(first) = [1] pi(mark) = 1 pi(add) = [] pi(|0|) = [] pi(if) = [1] pi(false) = [] pi(active) = 1 pi(nil) = [] The next rules are strictly ordered: p1, p2, p3, p4, p5, p6, p7, p8, p9, p10, p11, p12, p13, p14, p15, p16, p17, p18, p19 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: s#(mark(X)) -> s#(X) p2: s#(active(X)) -> s#(X) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The set of usable rules consists of (no rules) Take the monotone reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order precedence: s# > active > mark argument filter: pi(s#) = 1 pi(mark) = [1] pi(active) = 1 2. lexicographic path order precedence: s# > active > mark argument filter: pi(s#) = 1 pi(mark) = [1] pi(active) = 1 3. lexicographic path order precedence: s# > active > mark argument filter: pi(s#) = 1 pi(mark) = [1] pi(active) = [1] The next rules are strictly ordered: p1, p2 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: add#(mark(X1),X2) -> add#(X1,X2) p2: add#(X1,active(X2)) -> add#(X1,X2) p3: add#(active(X1),X2) -> add#(X1,X2) p4: add#(X1,mark(X2)) -> add#(X1,X2) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The set of usable rules consists of (no rules) Take the monotone reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order precedence: add# > active > mark argument filter: pi(add#) = [1, 2] pi(mark) = 1 pi(active) = 1 2. lexicographic path order precedence: add# > active > mark argument filter: pi(add#) = [1, 2] pi(mark) = 1 pi(active) = 1 3. lexicographic path order precedence: add# > active > mark argument filter: pi(add#) = [1, 2] pi(mark) = [1] pi(active) = [1] The next rules are strictly ordered: p1, p2, p3, p4 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: cons#(mark(X1),X2) -> cons#(X1,X2) p2: cons#(X1,active(X2)) -> cons#(X1,X2) p3: cons#(active(X1),X2) -> cons#(X1,X2) p4: cons#(X1,mark(X2)) -> cons#(X1,X2) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The set of usable rules consists of (no rules) Take the monotone reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order precedence: cons# > active > mark argument filter: pi(cons#) = [1, 2] pi(mark) = 1 pi(active) = 1 2. lexicographic path order precedence: cons# > active > mark argument filter: pi(cons#) = [1, 2] pi(mark) = 1 pi(active) = 1 3. lexicographic path order precedence: cons# > active > mark argument filter: pi(cons#) = [1, 2] pi(mark) = [1] pi(active) = [1] The next rules are strictly ordered: p1, p2, p3, p4 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: first#(mark(X1),X2) -> first#(X1,X2) p2: first#(X1,active(X2)) -> first#(X1,X2) p3: first#(active(X1),X2) -> first#(X1,X2) p4: first#(X1,mark(X2)) -> first#(X1,X2) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The set of usable rules consists of (no rules) Take the monotone reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order precedence: first# > active > mark argument filter: pi(first#) = [1, 2] pi(mark) = 1 pi(active) = 1 2. lexicographic path order precedence: first# > active > mark argument filter: pi(first#) = [1, 2] pi(mark) = 1 pi(active) = 1 3. lexicographic path order precedence: first# > active > mark argument filter: pi(first#) = [1, 2] pi(mark) = [1] pi(active) = [1] The next rules are strictly ordered: p1, p2, p3, p4 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: from#(mark(X)) -> from#(X) p2: from#(active(X)) -> from#(X) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The set of usable rules consists of (no rules) Take the monotone reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order precedence: from# > active > mark argument filter: pi(from#) = 1 pi(mark) = [1] pi(active) = 1 2. lexicographic path order precedence: from# > active > mark argument filter: pi(from#) = 1 pi(mark) = [1] pi(active) = 1 3. lexicographic path order precedence: from# > active > mark argument filter: pi(from#) = 1 pi(mark) = [1] pi(active) = [1] The next rules are strictly ordered: p1, p2 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: and#(mark(X1),X2) -> and#(X1,X2) p2: and#(X1,active(X2)) -> and#(X1,X2) p3: and#(active(X1),X2) -> and#(X1,X2) p4: and#(X1,mark(X2)) -> and#(X1,X2) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The set of usable rules consists of (no rules) Take the monotone reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order precedence: and# > active > mark argument filter: pi(and#) = [1, 2] pi(mark) = 1 pi(active) = 1 2. lexicographic path order precedence: and# > active > mark argument filter: pi(and#) = [1, 2] pi(mark) = 1 pi(active) = 1 3. lexicographic path order precedence: and# > active > mark argument filter: pi(and#) = [1, 2] pi(mark) = [1] pi(active) = [1] The next rules are strictly ordered: p1, p2, p3, p4 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: if#(mark(X1),X2,X3) -> if#(X1,X2,X3) p2: if#(X1,X2,active(X3)) -> if#(X1,X2,X3) p3: if#(X1,active(X2),X3) -> if#(X1,X2,X3) p4: if#(active(X1),X2,X3) -> if#(X1,X2,X3) p5: if#(X1,X2,mark(X3)) -> if#(X1,X2,X3) p6: if#(X1,mark(X2),X3) -> if#(X1,X2,X3) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order precedence: if# > active > mark argument filter: pi(if#) = [1, 3] pi(mark) = 1 pi(active) = 1 2. lexicographic path order precedence: if# > active > mark argument filter: pi(if#) = 1 pi(mark) = 1 pi(active) = 1 3. lexicographic path order precedence: if# > active > mark argument filter: pi(if#) = [1] pi(mark) = [1] pi(active) = [1] The next rules are strictly ordered: p1, p4 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: if#(X1,X2,active(X3)) -> if#(X1,X2,X3) p2: if#(X1,active(X2),X3) -> if#(X1,X2,X3) p3: if#(X1,X2,mark(X3)) -> if#(X1,X2,X3) p4: if#(X1,mark(X2),X3) -> if#(X1,X2,X3) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The estimated dependency graph contains the following SCCs: {p1, p2, p3, p4} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: if#(X1,X2,active(X3)) -> if#(X1,X2,X3) p2: if#(X1,mark(X2),X3) -> if#(X1,X2,X3) p3: if#(X1,X2,mark(X3)) -> if#(X1,X2,X3) p4: if#(X1,active(X2),X3) -> if#(X1,X2,X3) and R consists of: r1: active(and(true(),X)) -> mark(X) r2: active(and(false(),Y)) -> mark(false()) r3: active(if(true(),X,Y)) -> mark(X) r4: active(if(false(),X,Y)) -> mark(Y) r5: active(add(|0|(),X)) -> mark(X) r6: active(add(s(X),Y)) -> mark(s(add(X,Y))) r7: active(first(|0|(),X)) -> mark(nil()) r8: active(first(s(X),cons(Y,Z))) -> mark(cons(Y,first(X,Z))) r9: active(from(X)) -> mark(cons(X,from(s(X)))) r10: mark(and(X1,X2)) -> active(and(mark(X1),X2)) r11: mark(true()) -> active(true()) r12: mark(false()) -> active(false()) r13: mark(if(X1,X2,X3)) -> active(if(mark(X1),X2,X3)) r14: mark(add(X1,X2)) -> active(add(mark(X1),X2)) r15: mark(|0|()) -> active(|0|()) r16: mark(s(X)) -> active(s(X)) r17: mark(first(X1,X2)) -> active(first(mark(X1),mark(X2))) r18: mark(nil()) -> active(nil()) r19: mark(cons(X1,X2)) -> active(cons(X1,X2)) r20: mark(from(X)) -> active(from(X)) r21: and(mark(X1),X2) -> and(X1,X2) r22: and(X1,mark(X2)) -> and(X1,X2) r23: and(active(X1),X2) -> and(X1,X2) r24: and(X1,active(X2)) -> and(X1,X2) r25: if(mark(X1),X2,X3) -> if(X1,X2,X3) r26: if(X1,mark(X2),X3) -> if(X1,X2,X3) r27: if(X1,X2,mark(X3)) -> if(X1,X2,X3) r28: if(active(X1),X2,X3) -> if(X1,X2,X3) r29: if(X1,active(X2),X3) -> if(X1,X2,X3) r30: if(X1,X2,active(X3)) -> if(X1,X2,X3) r31: add(mark(X1),X2) -> add(X1,X2) r32: add(X1,mark(X2)) -> add(X1,X2) r33: add(active(X1),X2) -> add(X1,X2) r34: add(X1,active(X2)) -> add(X1,X2) r35: s(mark(X)) -> s(X) r36: s(active(X)) -> s(X) r37: first(mark(X1),X2) -> first(X1,X2) r38: first(X1,mark(X2)) -> first(X1,X2) r39: first(active(X1),X2) -> first(X1,X2) r40: first(X1,active(X2)) -> first(X1,X2) r41: cons(mark(X1),X2) -> cons(X1,X2) r42: cons(X1,mark(X2)) -> cons(X1,X2) r43: cons(active(X1),X2) -> cons(X1,X2) r44: cons(X1,active(X2)) -> cons(X1,X2) r45: from(mark(X)) -> from(X) r46: from(active(X)) -> from(X) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order precedence: if# > mark > active argument filter: pi(if#) = [1, 2, 3] pi(active) = [1] pi(mark) = 1 2. lexicographic path order precedence: if# > mark > active argument filter: pi(if#) = [1, 2, 3] pi(active) = [1] pi(mark) = [1] 3. lexicographic path order precedence: if# > mark > active argument filter: pi(if#) = 1 pi(active) = [] pi(mark) = [] The next rules are strictly ordered: p1, p2, p3, p4 We remove them from the problem. Then no dependency pair remains.