YES We show the termination of the TRS R: p(s(x)) -> x plus(x,|0|()) -> x plus(|0|(),y) -> y plus(s(x),y) -> s(plus(x,y)) plus(s(x),y) -> s(plus(p(s(x)),y)) plus(x,s(y)) -> s(plus(x,p(s(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: plus#(s(x),y) -> plus#(p(s(x)),y) p3: plus#(s(x),y) -> p#(s(x)) p4: plus#(x,s(y)) -> plus#(x,p(s(y))) p5: plus#(x,s(y)) -> p#(s(y)) p6: times#(s(x),y) -> plus#(y,times(x,y)) p7: times#(s(x),y) -> times#(x,y) p8: div#(x,y) -> quot#(x,y,y) p9: quot#(s(x),s(y),z) -> quot#(x,y,z) p10: quot#(x,|0|(),s(z)) -> div#(x,s(z)) p11: div#(div(x,y),z) -> div#(x,times(y,z)) p12: div#(div(x,y),z) -> times#(y,z) p13: eq#(s(x),s(y)) -> eq#(x,y) p14: divides#(y,x) -> eq#(x,times(div(x,y),y)) p15: divides#(y,x) -> times#(div(x,y),y) p16: divides#(y,x) -> div#(x,y) p17: prime#(s(s(x))) -> pr#(s(s(x)),s(x)) p18: pr#(x,s(s(y))) -> if#(divides(s(s(y)),x),x,s(y)) p19: pr#(x,s(s(y))) -> divides#(s(s(y)),x) p20: if#(false(),x,y) -> pr#(x,y) and R consists of: r1: p(s(x)) -> x r2: plus(x,|0|()) -> x r3: plus(|0|(),y) -> y r4: plus(s(x),y) -> s(plus(x,y)) r5: plus(s(x),y) -> s(plus(p(s(x)),y)) r6: plus(x,s(y)) -> s(plus(x,p(s(y)))) r7: times(|0|(),y) -> |0|() r8: times(s(|0|()),y) -> y r9: times(s(x),y) -> plus(y,times(x,y)) r10: div(|0|(),y) -> |0|() r11: div(x,y) -> quot(x,y,y) r12: quot(|0|(),s(y),z) -> |0|() r13: quot(s(x),s(y),z) -> quot(x,y,z) r14: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r15: div(div(x,y),z) -> div(x,times(y,z)) r16: eq(|0|(),|0|()) -> true() r17: eq(s(x),|0|()) -> false() r18: eq(|0|(),s(y)) -> false() r19: eq(s(x),s(y)) -> eq(x,y) r20: divides(y,x) -> eq(x,times(div(x,y),y)) r21: prime(s(s(x))) -> pr(s(s(x)),s(x)) r22: pr(x,s(|0|())) -> true() r23: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r24: if(true(),x,y) -> false() r25: if(false(),x,y) -> pr(x,y) The estimated dependency graph contains the following SCCs: {p18, p20} {p8, p9, p10, p11} {p7} {p1, p2, p4} {p13} -- 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: p(s(x)) -> x r2: plus(x,|0|()) -> x r3: plus(|0|(),y) -> y r4: plus(s(x),y) -> s(plus(x,y)) r5: plus(s(x),y) -> s(plus(p(s(x)),y)) r6: plus(x,s(y)) -> s(plus(x,p(s(y)))) r7: times(|0|(),y) -> |0|() r8: times(s(|0|()),y) -> y r9: times(s(x),y) -> plus(y,times(x,y)) r10: div(|0|(),y) -> |0|() r11: div(x,y) -> quot(x,y,y) r12: quot(|0|(),s(y),z) -> |0|() r13: quot(s(x),s(y),z) -> quot(x,y,z) r14: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r15: div(div(x,y),z) -> div(x,times(y,z)) r16: eq(|0|(),|0|()) -> true() r17: eq(s(x),|0|()) -> false() r18: eq(|0|(),s(y)) -> false() r19: eq(s(x),s(y)) -> eq(x,y) r20: divides(y,x) -> eq(x,times(div(x,y),y)) r21: prime(s(s(x))) -> pr(s(s(x)),s(x)) r22: pr(x,s(|0|())) -> true() r23: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r24: if(true(),x,y) -> false() r25: if(false(),x,y) -> pr(x,y) The set of usable rules consists of r10, r16, r17, r18, r19, r20 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: if#_A(x1,x2,x3) = x3 false_A() = 1 pr#_A(x1,x2) = x2 s_A(x1) = x1 + 3 divides_A(x1,x2) = x1 + 1 div_A(x1,x2) = x1 + x2 + 1 |0|_A() = 4 eq_A(x1,x2) = 1 true_A() = 0 times_A(x1,x2) = 2 if#!_A(x1,x2,x3) = 10 false!_A() = 1 pr#!_A(x1,x2) = 9 s!_A(x1) = 10 divides!_A(x1,x2) = 8 div!_A(x1,x2) = 12 |0|!_A() = 11 eq!_A(x1,x2) = 3 true!_A() = 2 times!_A(x1,x2) = x1 + 11 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: if#_A(x1,x2,x3) = max{1, x1 - 12, x2 - 12, x3 - 3} false_A = 7 pr#_A(x1,x2) = max{1, x1 - 12, x2 - 4} s_A(x1) = 2 divides_A(x1,x2) = x1 + 8 div_A(x1,x2) = max{7, x1 + 5, x2 - 12} |0|_A = 8 eq_A(x1,x2) = 7 true_A = 7 times_A(x1,x2) = max{6, x2 - 14} if#!_A(x1,x2,x3) = max{0, x1 - 12, x3 - 3} false!_A = 0 pr#!_A(x1,x2) = max{0, x2 - 12} s!_A(x1) = 0 divides!_A(x1,x2) = 0 div!_A(x1,x2) = max{x1 + 33, x2 + 14} |0|!_A = 17 eq!_A(x1,x2) = 0 true!_A = 1 times!_A(x1,x2) = max{18, x2 - 4} partial status: pi(if#) = [3] pi(false) = [] pi(pr#) = [2] pi(s) = [1] pi(divides) = [] pi(div) = [2] pi(|0|) = [] pi(eq) = [] pi(true) = [] pi(times) = [1] 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: p(s(x)) -> x r2: plus(x,|0|()) -> x r3: plus(|0|(),y) -> y r4: plus(s(x),y) -> s(plus(x,y)) r5: plus(s(x),y) -> s(plus(p(s(x)),y)) r6: plus(x,s(y)) -> s(plus(x,p(s(y)))) r7: times(|0|(),y) -> |0|() r8: times(s(|0|()),y) -> y r9: times(s(x),y) -> plus(y,times(x,y)) r10: div(|0|(),y) -> |0|() r11: div(x,y) -> quot(x,y,y) r12: quot(|0|(),s(y),z) -> |0|() r13: quot(s(x),s(y),z) -> quot(x,y,z) r14: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r15: div(div(x,y),z) -> div(x,times(y,z)) r16: eq(|0|(),|0|()) -> true() r17: eq(s(x),|0|()) -> false() r18: eq(|0|(),s(y)) -> false() r19: eq(s(x),s(y)) -> eq(x,y) r20: divides(y,x) -> eq(x,times(div(x,y),y)) r21: prime(s(s(x))) -> pr(s(s(x)),s(x)) r22: pr(x,s(|0|())) -> true() r23: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r24: if(true(),x,y) -> false() r25: if(false(),x,y) -> pr(x,y) The set of usable rules consists of r3, r8, r12 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: div#_A(x1,x2) = x1 div_A(x1,x2) = x1 + x2 + 1 times_A(x1,x2) = x2 + 2 quot#_A(x1,x2,x3) = x1 |0|_A() = 3 s_A(x1) = x1 + 2 plus_A(x1,x2) = x2 + 1 quot_A(x1,x2,x3) = x1 + 2 div#!_A(x1,x2) = x1 + 5 div!_A(x1,x2) = 4 times!_A(x1,x2) = 7 quot#!_A(x1,x2,x3) = x1 + 5 |0|!_A() = 2 s!_A(x1) = 2 plus!_A(x1,x2) = 1 quot!_A(x1,x2,x3) = x1 + x3 + 3 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: div#_A(x1,x2) = 1 div_A(x1,x2) = max{18, x1 + 8, x2 + 8} times_A(x1,x2) = max{x1 - 16, x2} quot#_A(x1,x2,x3) = 1 |0|_A = 0 s_A(x1) = max{0, x1 - 7} plus_A(x1,x2) = max{8, x2} quot_A(x1,x2,x3) = max{0, x1 - 1, x2 - 1, x3 - 1} div#!_A(x1,x2) = x1 + 6 div!_A(x1,x2) = 3 times!_A(x1,x2) = max{1, x1 - 19, x2 - 10} quot#!_A(x1,x2,x3) = x1 + 6 |0|!_A = 2 s!_A(x1) = 4 plus!_A(x1,x2) = max{22, x1 + 21, x2 - 9} quot!_A(x1,x2,x3) = max{x1 + 15, x2 + 5, x3 + 15} partial status: pi(div#) = [] pi(div) = [] pi(times) = [2] pi(quot#) = [] pi(|0|) = [] pi(s) = [] pi(plus) = [1, 2] pi(quot) = [] The following rules are removed: p1, p4 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: div#(x,y) -> quot#(x,y,y) p2: quot#(x,|0|(),s(z)) -> div#(x,s(z)) and R consists of: r1: p(s(x)) -> x r2: plus(x,|0|()) -> x r3: plus(|0|(),y) -> y r4: plus(s(x),y) -> s(plus(x,y)) r5: plus(s(x),y) -> s(plus(p(s(x)),y)) r6: plus(x,s(y)) -> s(plus(x,p(s(y)))) r7: times(|0|(),y) -> |0|() r8: times(s(|0|()),y) -> y r9: times(s(x),y) -> plus(y,times(x,y)) r10: div(|0|(),y) -> |0|() r11: div(x,y) -> quot(x,y,y) r12: quot(|0|(),s(y),z) -> |0|() r13: quot(s(x),s(y),z) -> quot(x,y,z) r14: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r15: div(div(x,y),z) -> div(x,times(y,z)) r16: eq(|0|(),|0|()) -> true() r17: eq(s(x),|0|()) -> false() r18: eq(|0|(),s(y)) -> false() r19: eq(s(x),s(y)) -> eq(x,y) r20: divides(y,x) -> eq(x,times(div(x,y),y)) r21: prime(s(s(x))) -> pr(s(s(x)),s(x)) r22: pr(x,s(|0|())) -> true() r23: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r24: if(true(),x,y) -> false() r25: if(false(),x,y) -> pr(x,y) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: div#(x,y) -> quot#(x,y,y) p2: quot#(x,|0|(),s(z)) -> div#(x,s(z)) and R consists of: r1: p(s(x)) -> x r2: plus(x,|0|()) -> x r3: plus(|0|(),y) -> y r4: plus(s(x),y) -> s(plus(x,y)) r5: plus(s(x),y) -> s(plus(p(s(x)),y)) r6: plus(x,s(y)) -> s(plus(x,p(s(y)))) r7: times(|0|(),y) -> |0|() r8: times(s(|0|()),y) -> y r9: times(s(x),y) -> plus(y,times(x,y)) r10: div(|0|(),y) -> |0|() r11: div(x,y) -> quot(x,y,y) r12: quot(|0|(),s(y),z) -> |0|() r13: quot(s(x),s(y),z) -> quot(x,y,z) r14: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r15: div(div(x,y),z) -> div(x,times(y,z)) r16: eq(|0|(),|0|()) -> true() r17: eq(s(x),|0|()) -> false() r18: eq(|0|(),s(y)) -> false() r19: eq(s(x),s(y)) -> eq(x,y) r20: divides(y,x) -> eq(x,times(div(x,y),y)) r21: prime(s(s(x))) -> pr(s(s(x)),s(x)) r22: pr(x,s(|0|())) -> true() r23: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r24: if(true(),x,y) -> false() r25: if(false(),x,y) -> pr(x,y) The set of usable rules consists of 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: div#_A(x1,x2) = 0 quot#_A(x1,x2,x3) = 0 |0|_A() = 7 s_A(x1) = 3 times_A(x1,x2) = x1 + 1 div#!_A(x1,x2) = x1 + x2 + 1 quot#!_A(x1,x2,x3) = x1 + x2 |0|!_A() = 5 s!_A(x1) = x1 + 6 times!_A(x1,x2) = x2 + 16 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: div#_A(x1,x2) = max{1, x1 - 2, x2 - 49} quot#_A(x1,x2,x3) = max{1, x1 - 2, x2 - 49} |0|_A = 30 s_A(x1) = 48 times_A(x1,x2) = max{55, x1 + 6, x2 + 53} div#!_A(x1,x2) = 29 quot#!_A(x1,x2,x3) = 0 |0|!_A = 28 s!_A(x1) = 0 times!_A(x1,x2) = max{26, x1 + 6, x2 - 53} partial status: pi(div#) = [1] pi(quot#) = [1] pi(|0|) = [] pi(s) = [] pi(times) = [1, 2] 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: times#(s(x),y) -> times#(x,y) and R consists of: r1: p(s(x)) -> x r2: plus(x,|0|()) -> x r3: plus(|0|(),y) -> y r4: plus(s(x),y) -> s(plus(x,y)) r5: plus(s(x),y) -> s(plus(p(s(x)),y)) r6: plus(x,s(y)) -> s(plus(x,p(s(y)))) r7: times(|0|(),y) -> |0|() r8: times(s(|0|()),y) -> y r9: times(s(x),y) -> plus(y,times(x,y)) r10: div(|0|(),y) -> |0|() r11: div(x,y) -> quot(x,y,y) r12: quot(|0|(),s(y),z) -> |0|() r13: quot(s(x),s(y),z) -> quot(x,y,z) r14: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r15: div(div(x,y),z) -> div(x,times(y,z)) r16: eq(|0|(),|0|()) -> true() r17: eq(s(x),|0|()) -> false() r18: eq(|0|(),s(y)) -> false() r19: eq(s(x),s(y)) -> eq(x,y) r20: divides(y,x) -> eq(x,times(div(x,y),y)) r21: prime(s(s(x))) -> pr(s(s(x)),s(x)) r22: pr(x,s(|0|())) -> true() r23: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r24: if(true(),x,y) -> false() r25: if(false(),x,y) -> pr(x,y) The set of usable rules consists of 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: times#_A(x1,x2) = x1 s_A(x1) = x1 + 3 times_A(x1,x2) = x1 + x2 + 5 |0|_A() = 6 times#!_A(x1,x2) = x1 s!_A(x1) = 6 times!_A(x1,x2) = 7 |0|!_A() = 5 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: times#_A(x1,x2) = 0 s_A(x1) = max{8, x1 - 18} times_A(x1,x2) = max{10, x1 + 4, x2 - 124} |0|_A = 11 times#!_A(x1,x2) = max{22, x1 - 9, x2 - 1} s!_A(x1) = x1 + 21 times!_A(x1,x2) = max{81, x2 + 4} |0|!_A = 1 partial status: pi(times#) = [] pi(s) = [1] pi(times) = [] pi(|0|) = [] 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) p2: plus#(x,s(y)) -> plus#(x,p(s(y))) p3: plus#(s(x),y) -> plus#(p(s(x)),y) and R consists of: r1: p(s(x)) -> x r2: plus(x,|0|()) -> x r3: plus(|0|(),y) -> y r4: plus(s(x),y) -> s(plus(x,y)) r5: plus(s(x),y) -> s(plus(p(s(x)),y)) r6: plus(x,s(y)) -> s(plus(x,p(s(y)))) r7: times(|0|(),y) -> |0|() r8: times(s(|0|()),y) -> y r9: times(s(x),y) -> plus(y,times(x,y)) r10: div(|0|(),y) -> |0|() r11: div(x,y) -> quot(x,y,y) r12: quot(|0|(),s(y),z) -> |0|() r13: quot(s(x),s(y),z) -> quot(x,y,z) r14: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r15: div(div(x,y),z) -> div(x,times(y,z)) r16: eq(|0|(),|0|()) -> true() r17: eq(s(x),|0|()) -> false() r18: eq(|0|(),s(y)) -> false() r19: eq(s(x),s(y)) -> eq(x,y) r20: divides(y,x) -> eq(x,times(div(x,y),y)) r21: prime(s(s(x))) -> pr(s(s(x)),s(x)) r22: pr(x,s(|0|())) -> true() r23: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r24: if(true(),x,y) -> false() r25: if(false(),x,y) -> pr(x,y) The set of usable rules consists of r1 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: plus#_A(x1,x2) = x2 s_A(x1) = x1 + 2 p_A(x1) = x1 plus#!_A(x1,x2) = x1 + 1 s!_A(x1) = x1 + 4 p!_A(x1) = 0 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: plus#_A(x1,x2) = 0 s_A(x1) = x1 + 53 p_A(x1) = max{1, x1 - 50} plus#!_A(x1,x2) = x2 + 56 s!_A(x1) = 46 p!_A(x1) = 55 partial status: pi(plus#) = [2] pi(s) = [1] pi(p) = [1] The following rules are removed: p1, p2 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: plus#(s(x),y) -> plus#(p(s(x)),y) and R consists of: r1: p(s(x)) -> x r2: plus(x,|0|()) -> x r3: plus(|0|(),y) -> y r4: plus(s(x),y) -> s(plus(x,y)) r5: plus(s(x),y) -> s(plus(p(s(x)),y)) r6: plus(x,s(y)) -> s(plus(x,p(s(y)))) r7: times(|0|(),y) -> |0|() r8: times(s(|0|()),y) -> y r9: times(s(x),y) -> plus(y,times(x,y)) r10: div(|0|(),y) -> |0|() r11: div(x,y) -> quot(x,y,y) r12: quot(|0|(),s(y),z) -> |0|() r13: quot(s(x),s(y),z) -> quot(x,y,z) r14: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r15: div(div(x,y),z) -> div(x,times(y,z)) r16: eq(|0|(),|0|()) -> true() r17: eq(s(x),|0|()) -> false() r18: eq(|0|(),s(y)) -> false() r19: eq(s(x),s(y)) -> eq(x,y) r20: divides(y,x) -> eq(x,times(div(x,y),y)) r21: prime(s(s(x))) -> pr(s(s(x)),s(x)) r22: pr(x,s(|0|())) -> true() r23: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r24: if(true(),x,y) -> false() r25: if(false(),x,y) -> pr(x,y) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: plus#(s(x),y) -> plus#(p(s(x)),y) and R consists of: r1: p(s(x)) -> x r2: plus(x,|0|()) -> x r3: plus(|0|(),y) -> y r4: plus(s(x),y) -> s(plus(x,y)) r5: plus(s(x),y) -> s(plus(p(s(x)),y)) r6: plus(x,s(y)) -> s(plus(x,p(s(y)))) r7: times(|0|(),y) -> |0|() r8: times(s(|0|()),y) -> y r9: times(s(x),y) -> plus(y,times(x,y)) r10: div(|0|(),y) -> |0|() r11: div(x,y) -> quot(x,y,y) r12: quot(|0|(),s(y),z) -> |0|() r13: quot(s(x),s(y),z) -> quot(x,y,z) r14: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r15: div(div(x,y),z) -> div(x,times(y,z)) r16: eq(|0|(),|0|()) -> true() r17: eq(s(x),|0|()) -> false() r18: eq(|0|(),s(y)) -> false() r19: eq(s(x),s(y)) -> eq(x,y) r20: divides(y,x) -> eq(x,times(div(x,y),y)) r21: prime(s(s(x))) -> pr(s(s(x)),s(x)) r22: pr(x,s(|0|())) -> true() r23: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r24: if(true(),x,y) -> false() r25: if(false(),x,y) -> pr(x,y) The set of usable rules consists of r1, r7, r10, r12 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: plus#_A(x1,x2) = x1 s_A(x1) = x1 + 4 p_A(x1) = x1 times_A(x1,x2) = x1 + 1 |0|_A() = 1 div_A(x1,x2) = x1 + 6 quot_A(x1,x2,x3) = x1 + 7 plus#!_A(x1,x2) = 7 s!_A(x1) = 7 p!_A(x1) = x1 + 2 times!_A(x1,x2) = x1 |0|!_A() = 0 div!_A(x1,x2) = x2 + 4 quot!_A(x1,x2,x3) = 7 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: plus#_A(x1,x2) = max{11, x1 - 117, x2 - 2} s_A(x1) = max{157, x1 + 42} p_A(x1) = max{129, x1 - 41} times_A(x1,x2) = max{155, x1 - 162} |0|_A = 1 div_A(x1,x2) = max{242, x1 + 39, x2 - 40} quot_A(x1,x2,x3) = max{243, x1 - 2, x2 - 158, x3 - 158} plus#!_A(x1,x2) = max{12, x1 - 2} s!_A(x1) = x1 + 40 p!_A(x1) = max{156, x1 - 158} times!_A(x1,x2) = max{2, x1 - 244} |0|!_A = 1 div!_A(x1,x2) = max{2, x2 - 118} quot!_A(x1,x2,x3) = max{3, x1 - 158, x2 - 158, x3 - 1} partial status: pi(plus#) = [2] pi(s) = [1] pi(p) = [1] pi(times) = [1] pi(|0|) = [] pi(div) = [2] pi(quot) = [3] 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: p(s(x)) -> x r2: plus(x,|0|()) -> x r3: plus(|0|(),y) -> y r4: plus(s(x),y) -> s(plus(x,y)) r5: plus(s(x),y) -> s(plus(p(s(x)),y)) r6: plus(x,s(y)) -> s(plus(x,p(s(y)))) r7: times(|0|(),y) -> |0|() r8: times(s(|0|()),y) -> y r9: times(s(x),y) -> plus(y,times(x,y)) r10: div(|0|(),y) -> |0|() r11: div(x,y) -> quot(x,y,y) r12: quot(|0|(),s(y),z) -> |0|() r13: quot(s(x),s(y),z) -> quot(x,y,z) r14: quot(x,|0|(),s(z)) -> s(div(x,s(z))) r15: div(div(x,y),z) -> div(x,times(y,z)) r16: eq(|0|(),|0|()) -> true() r17: eq(s(x),|0|()) -> false() r18: eq(|0|(),s(y)) -> false() r19: eq(s(x),s(y)) -> eq(x,y) r20: divides(y,x) -> eq(x,times(div(x,y),y)) r21: prime(s(s(x))) -> pr(s(s(x)),s(x)) r22: pr(x,s(|0|())) -> true() r23: pr(x,s(s(y))) -> if(divides(s(s(y)),x),x,s(y)) r24: if(true(),x,y) -> false() r25: if(false(),x,y) -> pr(x,y) The set of usable rules consists of r22 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!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: eq#_A(x1,x2) = x1 + x2 s_A(x1) = x1 + 5 pr_A(x1,x2) = 15 |0|_A() = 7 true_A() = 15 eq#!_A(x1,x2) = x1 + x2 + 9 s!_A(x1) = x1 + 8 pr!_A(x1,x2) = 9 |0|!_A() = 7 true!_A() = 6 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: eq#_A(x1,x2) = 0 s_A(x1) = 0 pr_A(x1,x2) = max{4, x1 - 8, x2 - 16} |0|_A = 7 true_A = 4 eq#!_A(x1,x2) = 0 s!_A(x1) = x1 pr!_A(x1,x2) = max{2, x2 - 16} |0|!_A = 0 true!_A = 1 partial status: pi(eq#) = [1] pi(s) = [1] pi(pr) = [1] pi(|0|) = [] pi(true) = [] The following rules are removed: p1 Then no dependency pair remains.