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: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: conviter#_A(x1,x2) = max{40, x1 + 37, x2 + 21} if#_A(x1,x2,x3) = max{x1 + 34, x2 + 33, x3 + 20} zero_A(x1) = max{2, x1 - 2} false_A = 6 half_A(x1) = max{3, x1 - 5} cons_A(x1,x2) = max{11, x1, x2 - 2} lastbit_A(x1) = max{19, x1 + 9} |0|_A = 2 s_A(x1) = max{19, x1 + 9} true_A = 1 precedence: s > lastbit > cons = |0| > if# = true > conviter# = zero = false = half partial status: pi(conviter#) = [2] pi(if#) = [1, 2, 3] pi(zero) = [] pi(false) = [] pi(half) = [] pi(cons) = [1] pi(lastbit) = [1] pi(|0|) = [] pi(s) = [1] pi(true) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: conviter#_A(x1,x2) = max{11, x2 + 9} if#_A(x1,x2,x3) = max{12, x1 + 7} zero_A(x1) = 1 false_A = 3 half_A(x1) = 0 cons_A(x1,x2) = 0 lastbit_A(x1) = x1 + 22 |0|_A = 10 s_A(x1) = x1 + 4 true_A = 11 precedence: conviter# = if# = zero = false = half = cons = lastbit = |0| = s = true partial status: pi(conviter#) = [2] pi(if#) = [] pi(zero) = [] pi(false) = [] pi(half) = [] pi(cons) = [] pi(lastbit) = [1] pi(|0|) = [] pi(s) = [1] pi(true) = [] The next rules are strictly ordered: p1 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: 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 estimated dependency graph contains the following SCCs: (no SCCs) -- 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 (no rules) Take the monotone reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: half#_A(x1) = max{2, x1 + 1} s_A(x1) = max{1, x1} precedence: half# = s partial status: pi(half#) = [1] pi(s) = [1] 2. weighted path order base order: max/plus interpretations on natural numbers: half#_A(x1) = x1 + 1 s_A(x1) = x1 precedence: half# = s partial status: pi(half#) = [1] pi(s) = [1] The next rules are strictly ordered: p1 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: 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 (no rules) Take the monotone reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: lastbit#_A(x1) = max{2, x1 + 1} s_A(x1) = max{1, x1} precedence: lastbit# = s partial status: pi(lastbit#) = [1] pi(s) = [1] 2. weighted path order base order: max/plus interpretations on natural numbers: lastbit#_A(x1) = x1 + 1 s_A(x1) = x1 precedence: lastbit# = s partial status: pi(lastbit#) = [1] pi(s) = [1] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.