YES We show the termination of the TRS R: plus(x,|0|()) -> x plus(|0|(),y) -> y plus(s(x),y) -> s(plus(x,y)) times(|0|(),y) -> |0|() times(s(|0|()),y) -> y times(s(x),y) -> plus(y,times(x,y)) div(|0|(),y) -> |0|() div(x,y) -> quot(x,y,y) quot(|0|(),s(y),z) -> |0|() quot(s(x),s(y),z) -> quot(x,y,z) quot(x,|0|(),s(z)) -> s(div(x,s(z))) div(div(x,y),z) -> div(x,times(y,z)) eq(|0|(),|0|()) -> true() eq(s(x),|0|()) -> false() eq(|0|(),s(y)) -> false() eq(s(x),s(y)) -> eq(x,y) divides(y,x) -> eq(x,times(div(x,y),y)) prime(s(s(x))) -> pr(s(s(x)),s(x)) pr(x,s(|0|())) -> true() pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) if(true(),x,y) -> false() if(false(),x,y) -> pr(x,y) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: plus#(s(x),y) -> plus#(x,y) p2: times#(s(x),y) -> plus#(y,times(x,y)) p3: times#(s(x),y) -> times#(x,y) p4: div#(x,y) -> quot#(x,y,y) p5: quot#(s(x),s(y),z) -> quot#(x,y,z) p6: quot#(x,|0|(),s(z)) -> div#(x,s(z)) p7: div#(div(x,y),z) -> div#(x,times(y,z)) p8: div#(div(x,y),z) -> times#(y,z) p9: eq#(s(x),s(y)) -> eq#(x,y) p10: divides#(y,x) -> eq#(x,times(div(x,y),y)) p11: divides#(y,x) -> times#(div(x,y),y) p12: divides#(y,x) -> div#(x,y) p13: prime#(s(s(x))) -> pr#(s(s(x)),s(x)) p14: pr#(x,s(s(y))) -> if#(divides(s(s(y)),x),x,s(y)) p15: pr#(x,s(s(y))) -> divides#(s(s(y)),x) p16: if#(false(),x,y) -> pr#(x,y) and R consists of: r1: plus(x,|0|()) -> x r2: plus(|0|(),y) -> y r3: plus(s(x),y) -> s(plus(x,y)) r4: times(|0|(),y) -> |0|() r5: times(s(|0|()),y) -> y r6: times(s(x),y) -> plus(y,times(x,y)) r7: div(|0|(),y) -> |0|() r8: div(x,y) -> quot(x,y,y) r9: quot(|0|(),s(y),z) -> |0|() r10: quot(s(x),s(y),z) -> quot(x,y,z) r11: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r12: div(div(x,y),z) -> div(x,times(y,z)) r13: eq(|0|(),|0|()) -> true() r14: eq(s(x),|0|()) -> false() r15: eq(|0|(),s(y)) -> false() r16: eq(s(x),s(y)) -> eq(x,y) r17: divides(y,x) -> eq(x,times(div(x,y),y)) r18: prime(s(s(x))) -> pr(s(s(x)),s(x)) r19: pr(x,s(|0|())) -> true() r20: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r21: if(true(),x,y) -> false() r22: if(false(),x,y) -> pr(x,y) The estimated dependency graph contains the following SCCs: {p14, p16} {p4, p5, p6, p7} {p3} {p1} {p9} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: if#(false(),x,y) -> pr#(x,y) p2: pr#(x,s(s(y))) -> if#(divides(s(s(y)),x),x,s(y)) and R consists of: r1: plus(x,|0|()) -> x r2: plus(|0|(),y) -> y r3: plus(s(x),y) -> s(plus(x,y)) r4: times(|0|(),y) -> |0|() r5: times(s(|0|()),y) -> y r6: times(s(x),y) -> plus(y,times(x,y)) r7: div(|0|(),y) -> |0|() r8: div(x,y) -> quot(x,y,y) r9: quot(|0|(),s(y),z) -> |0|() r10: quot(s(x),s(y),z) -> quot(x,y,z) r11: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r12: div(div(x,y),z) -> div(x,times(y,z)) r13: eq(|0|(),|0|()) -> true() r14: eq(s(x),|0|()) -> false() r15: eq(|0|(),s(y)) -> false() r16: eq(s(x),s(y)) -> eq(x,y) r17: divides(y,x) -> eq(x,times(div(x,y),y)) r18: prime(s(s(x))) -> pr(s(s(x)),s(x)) r19: pr(x,s(|0|())) -> true() r20: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r21: if(true(),x,y) -> false() r22: if(false(),x,y) -> pr(x,y) The set of usable rules consists of r9, r13, r14, r15, r16, r17 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: if#_A(x1,x2,x3) = max{2, x1 - 12, x2 - 17, x3 - 33} false_A = 13 pr#_A(x1,x2) = max{2, x1 - 17, x2 - 48} s_A(x1) = max{32, x1 + 15} divides_A(x1,x2) = max{13, x1 - 36} quot_A(x1,x2,x3) = max{36, x2 - 33, x3 - 33} |0|_A = 11 eq_A(x1,x2) = 13 true_A = 13 times_A(x1,x2) = max{30, x2 + 11} div_A(x1,x2) = 21 if#!_A(x1,x2,x3) = max{35, x1 - 12, x3 + 1} false!_A = 0 pr#!_A(x1,x2) = max{34, x2 - 11} s!_A(x1) = 0 divides!_A(x1,x2) = max{20, x1 - 49, x2 - 12} quot!_A(x1,x2,x3) = 0 |0|!_A = 2 eq!_A(x1,x2) = max{2, x1 - 12} true!_A = 1 times!_A(x1,x2) = 0 div!_A(x1,x2) = 0 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: if#_A(x1,x2,x3) = max{42, x1 + 15, x2 + 41, x3 + 7} false_A = 26 pr#_A(x1,x2) = max{42, x1 + 41, x2 - 8} s_A(x1) = 7 divides_A(x1,x2) = max{x1 - 1, x2 + 26} quot_A(x1,x2,x3) = max{37, x1 - 1} |0|_A = 37 eq_A(x1,x2) = 26 true_A = 26 times_A(x1,x2) = max{0, x1 - 44} div_A(x1,x2) = max{37, x1, x2} if#!_A(x1,x2,x3) = max{16, x1 - 7} false!_A = 13 pr#!_A(x1,x2) = 18 s!_A(x1) = 15 divides!_A(x1,x2) = max{17, x1 + 12, x2 - 39} quot!_A(x1,x2,x3) = max{6, x2 - 8} |0|!_A = 16 eq!_A(x1,x2) = max{16, x1 - 40} true!_A = 14 times!_A(x1,x2) = 4 div!_A(x1,x2) = x2 + 7 partial status: pi(if#) = [3] pi(false) = [] pi(pr#) = [2] pi(s) = [1] pi(divides) = [2] pi(quot) = [1] pi(|0|) = [] pi(eq) = [] pi(true) = [] pi(times) = [1, 2] pi(div) = [] 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: div#(div(x,y),z) -> div#(x,times(y,z)) p2: div#(x,y) -> quot#(x,y,y) p3: quot#(x,|0|(),s(z)) -> div#(x,s(z)) p4: quot#(s(x),s(y),z) -> quot#(x,y,z) and R consists of: r1: plus(x,|0|()) -> x r2: plus(|0|(),y) -> y r3: plus(s(x),y) -> s(plus(x,y)) r4: times(|0|(),y) -> |0|() r5: times(s(|0|()),y) -> y r6: times(s(x),y) -> plus(y,times(x,y)) r7: div(|0|(),y) -> |0|() r8: div(x,y) -> quot(x,y,y) r9: quot(|0|(),s(y),z) -> |0|() r10: quot(s(x),s(y),z) -> quot(x,y,z) r11: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r12: div(div(x,y),z) -> div(x,times(y,z)) r13: eq(|0|(),|0|()) -> true() r14: eq(s(x),|0|()) -> false() r15: eq(|0|(),s(y)) -> false() r16: eq(s(x),s(y)) -> eq(x,y) r17: divides(y,x) -> eq(x,times(div(x,y),y)) r18: prime(s(s(x))) -> pr(s(s(x)),s(x)) r19: pr(x,s(|0|())) -> true() r20: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r21: if(true(),x,y) -> false() r22: if(false(),x,y) -> pr(x,y) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: div#_A(x1,x2) = max{13, x2 - 13} div_A(x1,x2) = max{x1 + 14, x2 + 3} times_A(x1,x2) = max{26, x2} quot#_A(x1,x2,x3) = max{13, x3 - 14} |0|_A = 0 s_A(x1) = 13 plus_A(x1,x2) = max{26, x1, x2} div#!_A(x1,x2) = 0 div!_A(x1,x2) = max{28, x1 + 23, x2 + 1} times!_A(x1,x2) = 36 quot#!_A(x1,x2,x3) = 0 |0|!_A = 35 s!_A(x1) = 29 plus!_A(x1,x2) = 30 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: div#_A(x1,x2) = 1 div_A(x1,x2) = max{x1 + 3, x2 + 3} times_A(x1,x2) = x2 + 9 quot#_A(x1,x2,x3) = 1 |0|_A = 9 s_A(x1) = 0 plus_A(x1,x2) = max{9, x1 + 1, x2} div#!_A(x1,x2) = x2 + 6 div!_A(x1,x2) = max{23, x1 - 10, x2 - 17} times!_A(x1,x2) = max{24, x2 + 20} quot#!_A(x1,x2,x3) = max{x2 - 2, x3 + 3} |0|!_A = 21 s!_A(x1) = 8 plus!_A(x1,x2) = x2 + 10 partial status: pi(div#) = [1] pi(div) = [1, 2] pi(times) = [1, 2] pi(quot#) = [1] pi(|0|) = [] pi(s) = [1] pi(plus) = [1, 2] The following rules are removed: p1, p2, p3, p4 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: times#(s(x),y) -> times#(x,y) and R consists of: r1: plus(x,|0|()) -> x r2: plus(|0|(),y) -> y r3: plus(s(x),y) -> s(plus(x,y)) r4: times(|0|(),y) -> |0|() r5: times(s(|0|()),y) -> y r6: times(s(x),y) -> plus(y,times(x,y)) r7: div(|0|(),y) -> |0|() r8: div(x,y) -> quot(x,y,y) r9: quot(|0|(),s(y),z) -> |0|() r10: quot(s(x),s(y),z) -> quot(x,y,z) r11: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r12: div(div(x,y),z) -> div(x,times(y,z)) r13: eq(|0|(),|0|()) -> true() r14: eq(s(x),|0|()) -> false() r15: eq(|0|(),s(y)) -> false() r16: eq(s(x),s(y)) -> eq(x,y) r17: divides(y,x) -> eq(x,times(div(x,y),y)) r18: prime(s(s(x))) -> pr(s(s(x)),s(x)) r19: pr(x,s(|0|())) -> true() r20: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r21: if(true(),x,y) -> false() r22: if(false(),x,y) -> pr(x,y) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: times#_A(x1,x2) = 0 s_A(x1) = max{4, x1 - 10} times#!_A(x1,x2) = max{0, x1 - 80} s!_A(x1) = max{4, x1 - 79} 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: times#_A(x1,x2) = 0 s_A(x1) = max{7, x1 - 2} times#!_A(x1,x2) = max{6, x1 - 8, x2 - 1} s!_A(x1) = max{5, x1 - 66} partial status: pi(times#) = [1] pi(s) = [1] 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: plus#(s(x),y) -> plus#(x,y) and R consists of: r1: plus(x,|0|()) -> x r2: plus(|0|(),y) -> y r3: plus(s(x),y) -> s(plus(x,y)) r4: times(|0|(),y) -> |0|() r5: times(s(|0|()),y) -> y r6: times(s(x),y) -> plus(y,times(x,y)) r7: div(|0|(),y) -> |0|() r8: div(x,y) -> quot(x,y,y) r9: quot(|0|(),s(y),z) -> |0|() r10: quot(s(x),s(y),z) -> quot(x,y,z) r11: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r12: div(div(x,y),z) -> div(x,times(y,z)) r13: eq(|0|(),|0|()) -> true() r14: eq(s(x),|0|()) -> false() r15: eq(|0|(),s(y)) -> false() r16: eq(s(x),s(y)) -> eq(x,y) r17: divides(y,x) -> eq(x,times(div(x,y),y)) r18: prime(s(s(x))) -> pr(s(s(x)),s(x)) r19: pr(x,s(|0|())) -> true() r20: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r21: if(true(),x,y) -> false() r22: if(false(),x,y) -> pr(x,y) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: plus#_A(x1,x2) = 0 s_A(x1) = max{7, x1 - 10} plus#!_A(x1,x2) = max{1, x1 - 57} s!_A(x1) = max{2, x1 - 56} 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: plus#_A(x1,x2) = 0 s_A(x1) = max{11, x1 - 3} plus#!_A(x1,x2) = max{3, x1 - 12, x2 - 1} s!_A(x1) = max{2, x1 - 54} partial status: pi(plus#) = [1] pi(s) = [1] 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: eq#(s(x),s(y)) -> eq#(x,y) and R consists of: r1: plus(x,|0|()) -> x r2: plus(|0|(),y) -> y r3: plus(s(x),y) -> s(plus(x,y)) r4: times(|0|(),y) -> |0|() r5: times(s(|0|()),y) -> y r6: times(s(x),y) -> plus(y,times(x,y)) r7: div(|0|(),y) -> |0|() r8: div(x,y) -> quot(x,y,y) r9: quot(|0|(),s(y),z) -> |0|() r10: quot(s(x),s(y),z) -> quot(x,y,z) r11: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r12: div(div(x,y),z) -> div(x,times(y,z)) r13: eq(|0|(),|0|()) -> true() r14: eq(s(x),|0|()) -> false() r15: eq(|0|(),s(y)) -> false() r16: eq(s(x),s(y)) -> eq(x,y) r17: divides(y,x) -> eq(x,times(div(x,y),y)) r18: prime(s(s(x))) -> pr(s(s(x)),s(x)) r19: pr(x,s(|0|())) -> true() r20: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r21: if(true(),x,y) -> false() r22: if(false(),x,y) -> pr(x,y) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: eq#_A(x1,x2) = 0 s_A(x1) = max{10, x1 - 16} eq#!_A(x1,x2) = 1 s!_A(x1) = 3 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: eq#_A(x1,x2) = 0 s_A(x1) = max{33, x1 - 10} eq#!_A(x1,x2) = max{4, x1 - 139, x2 - 141} s!_A(x1) = max{3, x1 - 140} partial status: pi(eq#) = [2] pi(s) = [1] The following rules are removed: p1 Then no dependency pair remains.