YES We show the termination of the TRS R: half(|0|()) -> |0|() half(s(|0|())) -> |0|() half(s(s(x))) -> s(half(x)) lastbit(|0|()) -> |0|() lastbit(s(|0|())) -> s(|0|()) lastbit(s(s(x))) -> lastbit(x) zero(|0|()) -> true() zero(s(x)) -> false() conv(x) -> conviter(x,cons(|0|(),nil())) conviter(x,l) -> if(zero(x),x,l) if(true(),x,l) -> l if(false(),x,l) -> conviter(half(x),cons(lastbit(x),l)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: half#(s(s(x))) -> half#(x) p2: lastbit#(s(s(x))) -> lastbit#(x) p3: conv#(x) -> conviter#(x,cons(|0|(),nil())) p4: conviter#(x,l) -> if#(zero(x),x,l) p5: conviter#(x,l) -> zero#(x) p6: if#(false(),x,l) -> conviter#(half(x),cons(lastbit(x),l)) p7: if#(false(),x,l) -> half#(x) p8: if#(false(),x,l) -> lastbit#(x) and R consists of: r1: half(|0|()) -> |0|() r2: half(s(|0|())) -> |0|() r3: half(s(s(x))) -> s(half(x)) r4: lastbit(|0|()) -> |0|() r5: lastbit(s(|0|())) -> s(|0|()) r6: lastbit(s(s(x))) -> lastbit(x) r7: zero(|0|()) -> true() r8: zero(s(x)) -> false() r9: conv(x) -> conviter(x,cons(|0|(),nil())) r10: conviter(x,l) -> if(zero(x),x,l) r11: if(true(),x,l) -> l r12: if(false(),x,l) -> conviter(half(x),cons(lastbit(x),l)) The estimated dependency graph contains the following SCCs: {p4, p6} {p1} {p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: conviter#(x,l) -> if#(zero(x),x,l) p2: if#(false(),x,l) -> conviter#(half(x),cons(lastbit(x),l)) and R consists of: r1: half(|0|()) -> |0|() r2: half(s(|0|())) -> |0|() r3: half(s(s(x))) -> s(half(x)) r4: lastbit(|0|()) -> |0|() r5: lastbit(s(|0|())) -> s(|0|()) r6: lastbit(s(s(x))) -> lastbit(x) r7: zero(|0|()) -> true() r8: zero(s(x)) -> false() r9: conv(x) -> conviter(x,cons(|0|(),nil())) r10: conviter(x,l) -> if(zero(x),x,l) r11: if(true(),x,l) -> l r12: if(false(),x,l) -> conviter(half(x),cons(lastbit(x),l)) 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: max/plus interpretation on natural numbers: conviter#_A(x1,x2) = max{x1 + 5, x2 + 19} if#_A(x1,x2,x3) = max{x1 - 19, x2 + 4, x3 + 14} zero_A(x1) = max{18, x1 - 5} false_A = 54 half_A(x1) = max{8, x1 - 6} cons_A(x1,x2) = max{15, x2 - 39} lastbit_A(x1) = x1 + 59 |0|_A = 4 s_A(x1) = x1 + 63 true_A = 0 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: conviter#_A(x1,x2) = max{0, x1 - 17, x2 - 30} if#_A(x1,x2,x3) = max{0, x1 - 30, x2 - 17, x3 - 30} zero_A(x1) = max{14, x1 - 14} false_A = 0 half_A(x1) = 16 cons_A(x1,x2) = max{1, x1 - 3, x2} lastbit_A(x1) = 13 |0|_A = 1 s_A(x1) = max{13, x1} true_A = 0 conviter#!_A(x1,x2) = max{9, x1 - 17, x2 - 2} if#!_A(x1,x2,x3) = max{0, x2 - 18} zero!_A(x1) = max{8, x1 - 18} false!_A = 7 half!_A(x1) = max{13, x1 - 12} cons!_A(x1,x2) = max{1, x1 - 16, x2 - 13} lastbit!_A(x1) = max{8, x1 - 11} |0|!_A = 9 s!_A(x1) = max{14, x1 - 4} true!_A = 0 partial status: pi(conviter#) = [] pi(if#) = [] pi(zero) = [] pi(false) = [] pi(half) = [] pi(cons) = [] pi(lastbit) = [] pi(|0|) = [] pi(s) = [1] pi(true) = [] The following rules are removed: p1, p2 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: half#(s(s(x))) -> half#(x) and R consists of: r1: half(|0|()) -> |0|() r2: half(s(|0|())) -> |0|() r3: half(s(s(x))) -> s(half(x)) r4: lastbit(|0|()) -> |0|() r5: lastbit(s(|0|())) -> s(|0|()) r6: lastbit(s(s(x))) -> lastbit(x) r7: zero(|0|()) -> true() r8: zero(s(x)) -> false() r9: conv(x) -> conviter(x,cons(|0|(),nil())) r10: conviter(x,l) -> if(zero(x),x,l) r11: if(true(),x,l) -> l r12: if(false(),x,l) -> conviter(half(x),cons(lastbit(x),l)) The set of usable rules consists of r4, r5, r6, r8 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: half#_A(x1) = max{1, x1 - 33} s_A(x1) = max{19, x1 + 16} lastbit_A(x1) = max{20, x1 - 11} |0|_A = 2 zero_A(x1) = max{7, x1 - 20} false_A = 1 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: half#_A(x1) = 0 s_A(x1) = max{2, x1 - 5} lastbit_A(x1) = 2 |0|_A = 2 zero_A(x1) = max{24, x1 - 3} false_A = 1 half#!_A(x1) = max{1, x1 - 9} s!_A(x1) = max{3, x1 - 3} lastbit!_A(x1) = max{2, x1 - 9} |0|!_A = 1 zero!_A(x1) = max{3, x1 - 3} false!_A = 1 partial status: pi(half#) = [] pi(s) = [1] pi(lastbit) = [] pi(|0|) = [] pi(zero) = [] pi(false) = [] 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: lastbit#(s(s(x))) -> lastbit#(x) and R consists of: r1: half(|0|()) -> |0|() r2: half(s(|0|())) -> |0|() r3: half(s(s(x))) -> s(half(x)) r4: lastbit(|0|()) -> |0|() r5: lastbit(s(|0|())) -> s(|0|()) r6: lastbit(s(s(x))) -> lastbit(x) r7: zero(|0|()) -> true() r8: zero(s(x)) -> false() r9: conv(x) -> conviter(x,cons(|0|(),nil())) r10: conviter(x,l) -> if(zero(x),x,l) r11: if(true(),x,l) -> l r12: if(false(),x,l) -> conviter(half(x),cons(lastbit(x),l)) The set of usable rules consists of r1, r2 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: lastbit#_A(x1) = max{7, x1 - 21} s_A(x1) = max{19, x1 + 10} half_A(x1) = max{3, x1 + 1} |0|_A = 10 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: lastbit#_A(x1) = 0 s_A(x1) = max{1, x1 - 9} half_A(x1) = max{8, x1 - 20} |0|_A = 1 lastbit#!_A(x1) = max{5, x1 - 18} s!_A(x1) = max{5, x1 - 9} half!_A(x1) = max{4, x1 - 10} |0|!_A = 4 partial status: pi(lastbit#) = [] pi(s) = [1] pi(half) = [1] pi(|0|) = [] The following rules are removed: p1 Then no dependency pair remains.