YES We show the termination of the TRS R: __(__(X,Y),Z) -> __(X,__(Y,Z)) __(X,nil()) -> X __(nil(),X) -> X and(tt(),X) -> activate(X) isList(V) -> isNeList(activate(V)) isList(n__nil()) -> tt() isList(n____(V1,V2)) -> and(isList(activate(V1)),n__isList(activate(V2))) isNeList(V) -> isQid(activate(V)) isNeList(n____(V1,V2)) -> and(isList(activate(V1)),n__isNeList(activate(V2))) isNeList(n____(V1,V2)) -> and(isNeList(activate(V1)),n__isList(activate(V2))) isNePal(V) -> isQid(activate(V)) isNePal(n____(I,n____(P,I))) -> and(isQid(activate(I)),n__isPal(activate(P))) isPal(V) -> isNePal(activate(V)) isPal(n__nil()) -> tt() isQid(n__a()) -> tt() isQid(n__e()) -> tt() isQid(n__i()) -> tt() isQid(n__o()) -> tt() isQid(n__u()) -> tt() nil() -> n__nil() __(X1,X2) -> n____(X1,X2) isList(X) -> n__isList(X) isNeList(X) -> n__isNeList(X) isPal(X) -> n__isPal(X) a() -> n__a() e() -> n__e() i() -> n__i() o() -> n__o() u() -> n__u() activate(n__nil()) -> nil() activate(n____(X1,X2)) -> __(activate(X1),activate(X2)) activate(n__isList(X)) -> isList(X) activate(n__isNeList(X)) -> isNeList(X) activate(n__isPal(X)) -> isPal(X) activate(n__a()) -> a() activate(n__e()) -> e() activate(n__i()) -> i() activate(n__o()) -> o() activate(n__u()) -> u() activate(X) -> X -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: __#(__(X,Y),Z) -> __#(X,__(Y,Z)) p2: __#(__(X,Y),Z) -> __#(Y,Z) p3: and#(tt(),X) -> activate#(X) p4: isList#(V) -> isNeList#(activate(V)) p5: isList#(V) -> activate#(V) p6: isList#(n____(V1,V2)) -> and#(isList(activate(V1)),n__isList(activate(V2))) p7: isList#(n____(V1,V2)) -> isList#(activate(V1)) p8: isList#(n____(V1,V2)) -> activate#(V1) p9: isList#(n____(V1,V2)) -> activate#(V2) p10: isNeList#(V) -> isQid#(activate(V)) p11: isNeList#(V) -> activate#(V) p12: isNeList#(n____(V1,V2)) -> and#(isList(activate(V1)),n__isNeList(activate(V2))) p13: isNeList#(n____(V1,V2)) -> isList#(activate(V1)) p14: isNeList#(n____(V1,V2)) -> activate#(V1) p15: isNeList#(n____(V1,V2)) -> activate#(V2) p16: isNeList#(n____(V1,V2)) -> and#(isNeList(activate(V1)),n__isList(activate(V2))) p17: isNeList#(n____(V1,V2)) -> isNeList#(activate(V1)) p18: isNeList#(n____(V1,V2)) -> activate#(V1) p19: isNeList#(n____(V1,V2)) -> activate#(V2) p20: isNePal#(V) -> isQid#(activate(V)) p21: isNePal#(V) -> activate#(V) p22: isNePal#(n____(I,n____(P,I))) -> and#(isQid(activate(I)),n__isPal(activate(P))) p23: isNePal#(n____(I,n____(P,I))) -> isQid#(activate(I)) p24: isNePal#(n____(I,n____(P,I))) -> activate#(I) p25: isNePal#(n____(I,n____(P,I))) -> activate#(P) p26: isPal#(V) -> isNePal#(activate(V)) p27: isPal#(V) -> activate#(V) p28: activate#(n__nil()) -> nil#() p29: activate#(n____(X1,X2)) -> __#(activate(X1),activate(X2)) p30: activate#(n____(X1,X2)) -> activate#(X1) p31: activate#(n____(X1,X2)) -> activate#(X2) p32: activate#(n__isList(X)) -> isList#(X) p33: activate#(n__isNeList(X)) -> isNeList#(X) p34: activate#(n__isPal(X)) -> isPal#(X) p35: activate#(n__a()) -> a#() p36: activate#(n__e()) -> e#() p37: activate#(n__i()) -> i#() p38: activate#(n__o()) -> o#() p39: activate#(n__u()) -> u#() and R consists of: r1: __(__(X,Y),Z) -> __(X,__(Y,Z)) r2: __(X,nil()) -> X r3: __(nil(),X) -> X r4: and(tt(),X) -> activate(X) r5: isList(V) -> isNeList(activate(V)) r6: isList(n__nil()) -> tt() r7: isList(n____(V1,V2)) -> and(isList(activate(V1)),n__isList(activate(V2))) r8: isNeList(V) -> isQid(activate(V)) r9: isNeList(n____(V1,V2)) -> and(isList(activate(V1)),n__isNeList(activate(V2))) r10: isNeList(n____(V1,V2)) -> and(isNeList(activate(V1)),n__isList(activate(V2))) r11: isNePal(V) -> isQid(activate(V)) r12: isNePal(n____(I,n____(P,I))) -> and(isQid(activate(I)),n__isPal(activate(P))) r13: isPal(V) -> isNePal(activate(V)) r14: isPal(n__nil()) -> tt() r15: isQid(n__a()) -> tt() r16: isQid(n__e()) -> tt() r17: isQid(n__i()) -> tt() r18: isQid(n__o()) -> tt() r19: isQid(n__u()) -> tt() r20: nil() -> n__nil() r21: __(X1,X2) -> n____(X1,X2) r22: isList(X) -> n__isList(X) r23: isNeList(X) -> n__isNeList(X) r24: isPal(X) -> n__isPal(X) r25: a() -> n__a() r26: e() -> n__e() r27: i() -> n__i() r28: o() -> n__o() r29: u() -> n__u() r30: activate(n__nil()) -> nil() r31: activate(n____(X1,X2)) -> __(activate(X1),activate(X2)) r32: activate(n__isList(X)) -> isList(X) r33: activate(n__isNeList(X)) -> isNeList(X) r34: activate(n__isPal(X)) -> isPal(X) r35: activate(n__a()) -> a() r36: activate(n__e()) -> e() r37: activate(n__i()) -> i() r38: activate(n__o()) -> o() r39: activate(n__u()) -> u() r40: activate(X) -> X The estimated dependency graph contains the following SCCs: {p3, p4, p5, p6, p7, p8, p9, p11, p12, p13, p14, p15, p16, p17, p18, p19, p21, p22, p24, p25, p26, p27, p30, p31, p32, p33, p34} {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: isPal#(V) -> activate#(V) p2: activate#(n__isPal(X)) -> isPal#(X) p3: isPal#(V) -> isNePal#(activate(V)) p4: isNePal#(n____(I,n____(P,I))) -> activate#(P) p5: activate#(n__isNeList(X)) -> isNeList#(X) p6: isNeList#(n____(V1,V2)) -> activate#(V2) p7: activate#(n__isList(X)) -> isList#(X) p8: isList#(n____(V1,V2)) -> activate#(V2) p9: activate#(n____(X1,X2)) -> activate#(X2) p10: activate#(n____(X1,X2)) -> activate#(X1) p11: isList#(n____(V1,V2)) -> activate#(V1) p12: isList#(n____(V1,V2)) -> isList#(activate(V1)) p13: isList#(n____(V1,V2)) -> and#(isList(activate(V1)),n__isList(activate(V2))) p14: and#(tt(),X) -> activate#(X) p15: isList#(V) -> activate#(V) p16: isList#(V) -> isNeList#(activate(V)) p17: isNeList#(n____(V1,V2)) -> activate#(V1) p18: isNeList#(n____(V1,V2)) -> isNeList#(activate(V1)) p19: isNeList#(n____(V1,V2)) -> and#(isNeList(activate(V1)),n__isList(activate(V2))) p20: isNeList#(n____(V1,V2)) -> isList#(activate(V1)) p21: isNeList#(n____(V1,V2)) -> and#(isList(activate(V1)),n__isNeList(activate(V2))) p22: isNeList#(V) -> activate#(V) p23: isNePal#(n____(I,n____(P,I))) -> activate#(I) p24: isNePal#(n____(I,n____(P,I))) -> and#(isQid(activate(I)),n__isPal(activate(P))) p25: isNePal#(V) -> activate#(V) and R consists of: r1: __(__(X,Y),Z) -> __(X,__(Y,Z)) r2: __(X,nil()) -> X r3: __(nil(),X) -> X r4: and(tt(),X) -> activate(X) r5: isList(V) -> isNeList(activate(V)) r6: isList(n__nil()) -> tt() r7: isList(n____(V1,V2)) -> and(isList(activate(V1)),n__isList(activate(V2))) r8: isNeList(V) -> isQid(activate(V)) r9: isNeList(n____(V1,V2)) -> and(isList(activate(V1)),n__isNeList(activate(V2))) r10: isNeList(n____(V1,V2)) -> and(isNeList(activate(V1)),n__isList(activate(V2))) r11: isNePal(V) -> isQid(activate(V)) r12: isNePal(n____(I,n____(P,I))) -> and(isQid(activate(I)),n__isPal(activate(P))) r13: isPal(V) -> isNePal(activate(V)) r14: isPal(n__nil()) -> tt() r15: isQid(n__a()) -> tt() r16: isQid(n__e()) -> tt() r17: isQid(n__i()) -> tt() r18: isQid(n__o()) -> tt() r19: isQid(n__u()) -> tt() r20: nil() -> n__nil() r21: __(X1,X2) -> n____(X1,X2) r22: isList(X) -> n__isList(X) r23: isNeList(X) -> n__isNeList(X) r24: isPal(X) -> n__isPal(X) r25: a() -> n__a() r26: e() -> n__e() r27: i() -> n__i() r28: o() -> n__o() r29: u() -> n__u() r30: activate(n__nil()) -> nil() r31: activate(n____(X1,X2)) -> __(activate(X1),activate(X2)) r32: activate(n__isList(X)) -> isList(X) r33: activate(n__isNeList(X)) -> isNeList(X) r34: activate(n__isPal(X)) -> isPal(X) r35: activate(n__a()) -> a() r36: activate(n__e()) -> e() r37: activate(n__i()) -> i() r38: activate(n__o()) -> o() r39: activate(n__u()) -> u() r40: activate(X) -> 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 Take the reduction pair: matrix interpretations: carrier: N^3 order: lexicographic order interpretations: isPal#_A(x1) = x1 + (2,4,6) activate#_A(x1) = ((1,0,0),(0,1,0),(1,0,1)) x1 + (0,3,1) n__isPal_A(x1) = ((1,0,0),(1,0,0),(1,0,0)) x1 + (3,0,1) isNePal#_A(x1) = ((1,0,0),(0,1,0),(1,0,1)) x1 + (1,0,0) activate_A(x1) = x1 + (0,2,7) n_____A(x1,x2) = ((1,0,0),(1,0,0),(0,0,0)) x1 + x2 + (11,2,1) n__isNeList_A(x1) = x1 + (0,3,0) isNeList#_A(x1) = ((1,0,0),(0,1,0),(1,0,1)) x1 + (0,4,19) n__isList_A(x1) = ((1,0,0),(0,1,0),(1,0,1)) x1 + (9,6,18) isList#_A(x1) = ((1,0,0),(0,1,0),(1,0,0)) x1 + (1,0,27) and#_A(x1,x2) = ((1,0,0),(0,0,0),(1,0,0)) x2 + (2,6,21) isList_A(x1) = x1 + (9,7,19) tt_A() = (1,3,20) isNeList_A(x1) = x1 + (0,4,8) isQid_A(x1) = ((1,0,0),(0,0,0),(1,0,0)) x1 + (0,3,17) isNePal_A(x1) = x1 + (2,0,0) and_A(x1,x2) = ((0,0,0),(1,0,0),(1,0,0)) x1 + x2 + (1,1,11) ___A(x1,x2) = ((1,0,0),(1,0,0),(0,0,0)) x1 + x2 + (11,3,9) nil_A() = (1,2,8) isPal_A(x1) = ((1,0,0),(1,0,0),(0,0,0)) x1 + (3,1,21) n__nil_A() = (1,1,0) a_A() = (2,2,8) n__a_A() = (2,1,0) e_A() = (2,2,8) n__e_A() = (2,1,0) i_A() = (2,2,6) n__i_A() = (2,1,0) o_A() = (4,2,8) n__o_A() = (4,1,0) u_A() = (2,2,8) n__u_A() = (2,1,0) 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, p20, p21, p22, p23, p24, p25 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: __#(__(X,Y),Z) -> __#(X,__(Y,Z)) p2: __#(__(X,Y),Z) -> __#(Y,Z) and R consists of: r1: __(__(X,Y),Z) -> __(X,__(Y,Z)) r2: __(X,nil()) -> X r3: __(nil(),X) -> X r4: and(tt(),X) -> activate(X) r5: isList(V) -> isNeList(activate(V)) r6: isList(n__nil()) -> tt() r7: isList(n____(V1,V2)) -> and(isList(activate(V1)),n__isList(activate(V2))) r8: isNeList(V) -> isQid(activate(V)) r9: isNeList(n____(V1,V2)) -> and(isList(activate(V1)),n__isNeList(activate(V2))) r10: isNeList(n____(V1,V2)) -> and(isNeList(activate(V1)),n__isList(activate(V2))) r11: isNePal(V) -> isQid(activate(V)) r12: isNePal(n____(I,n____(P,I))) -> and(isQid(activate(I)),n__isPal(activate(P))) r13: isPal(V) -> isNePal(activate(V)) r14: isPal(n__nil()) -> tt() r15: isQid(n__a()) -> tt() r16: isQid(n__e()) -> tt() r17: isQid(n__i()) -> tt() r18: isQid(n__o()) -> tt() r19: isQid(n__u()) -> tt() r20: nil() -> n__nil() r21: __(X1,X2) -> n____(X1,X2) r22: isList(X) -> n__isList(X) r23: isNeList(X) -> n__isNeList(X) r24: isPal(X) -> n__isPal(X) r25: a() -> n__a() r26: e() -> n__e() r27: i() -> n__i() r28: o() -> n__o() r29: u() -> n__u() r30: activate(n__nil()) -> nil() r31: activate(n____(X1,X2)) -> __(activate(X1),activate(X2)) r32: activate(n__isList(X)) -> isList(X) r33: activate(n__isNeList(X)) -> isNeList(X) r34: activate(n__isPal(X)) -> isPal(X) r35: activate(n__a()) -> a() r36: activate(n__e()) -> e() r37: activate(n__i()) -> i() r38: activate(n__o()) -> o() r39: activate(n__u()) -> u() r40: activate(X) -> X The set of usable rules consists of r1, r2, r3, r21 Take the reduction pair: matrix interpretations: carrier: N^3 order: lexicographic order interpretations: __#_A(x1,x2) = x1 ___A(x1,x2) = ((1,0,0),(1,1,0),(0,0,1)) x1 + ((1,0,0),(0,1,0),(1,0,0)) x2 + (2,1,1) nil_A() = (1,1,1) n_____A(x1,x2) = (0,2,2) The next rules are strictly ordered: p1, p2 We remove them from the problem. Then no dependency pair remains.