YES We show the termination of the TRS R: if(true(),x,y) -> x if(false(),x,y) -> y eq(|0|(),|0|()) -> true() eq(|0|(),s(x)) -> false() eq(s(x),|0|()) -> false() eq(s(x),s(y)) -> eq(x,y) app(nil(),l) -> l app(cons(x,l1),l2) -> cons(x,app(l1,l2)) app(app(l1,l2),l3) -> app(l1,app(l2,l3)) mem(x,nil()) -> false() mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) ifmem(true(),x,l) -> true() ifmem(false(),x,l) -> mem(x,l) inter(x,nil()) -> nil() inter(nil(),x) -> nil() inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) ifinter(false(),x,l1,l2) -> inter(l1,l2) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: eq#(s(x),s(y)) -> eq#(x,y) p2: app#(cons(x,l1),l2) -> app#(l1,l2) p3: app#(app(l1,l2),l3) -> app#(l1,app(l2,l3)) p4: app#(app(l1,l2),l3) -> app#(l2,l3) p5: mem#(x,cons(y,l)) -> ifmem#(eq(x,y),x,l) p6: mem#(x,cons(y,l)) -> eq#(x,y) p7: ifmem#(false(),x,l) -> mem#(x,l) p8: inter#(app(l1,l2),l3) -> app#(inter(l1,l3),inter(l2,l3)) p9: inter#(app(l1,l2),l3) -> inter#(l1,l3) p10: inter#(app(l1,l2),l3) -> inter#(l2,l3) p11: inter#(l1,app(l2,l3)) -> app#(inter(l1,l2),inter(l1,l3)) p12: inter#(l1,app(l2,l3)) -> inter#(l1,l2) p13: inter#(l1,app(l2,l3)) -> inter#(l1,l3) p14: inter#(cons(x,l1),l2) -> ifinter#(mem(x,l2),x,l1,l2) p15: inter#(cons(x,l1),l2) -> mem#(x,l2) p16: inter#(l1,cons(x,l2)) -> ifinter#(mem(x,l1),x,l2,l1) p17: inter#(l1,cons(x,l2)) -> mem#(x,l1) p18: ifinter#(true(),x,l1,l2) -> inter#(l1,l2) p19: ifinter#(false(),x,l1,l2) -> inter#(l1,l2) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) The estimated dependency graph contains the following SCCs: {p9, p10, p12, p13, p14, p16, p18, p19} {p5, p7} {p1} {p2, p3, p4} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: ifinter#(false(),x,l1,l2) -> inter#(l1,l2) p2: inter#(l1,cons(x,l2)) -> ifinter#(mem(x,l1),x,l2,l1) p3: ifinter#(true(),x,l1,l2) -> inter#(l1,l2) p4: inter#(cons(x,l1),l2) -> ifinter#(mem(x,l2),x,l1,l2) p5: inter#(l1,app(l2,l3)) -> inter#(l1,l3) p6: inter#(l1,app(l2,l3)) -> inter#(l1,l2) p7: inter#(app(l1,l2),l3) -> inter#(l2,l3) p8: inter#(app(l1,l2),l3) -> inter#(l1,l3) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r10, r11, r12, r13 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: ifinter#_A(x1,x2,x3,x4) = 1 false_A = 4 inter#_A(x1,x2) = 1 cons_A(x1,x2) = max{5, x1 - 6, x2 - 6} mem_A(x1,x2) = x1 + 5 true_A = 4 app_A(x1,x2) = max{0, x1 - 6, x2 - 6} if_A(x1,x2,x3) = max{x2 + 1, x3 + 1} eq_A(x1,x2) = max{6, x1 - 6} |0|_A = 5 s_A(x1) = x1 + 13 nil_A = 5 ifmem_A(x1,x2,x3) = max{x1 - 7, x2 + 5} base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: ifinter#_A(x1,x2,x3,x4) = max{0, x1 - 97, x2 - 102, x3 - 1, x4 - 98} false_A = 0 inter#_A(x1,x2) = max{0, x1 - 98, x2 - 98} cons_A(x1,x2) = max{x1 - 4, x2 + 97} mem_A(x1,x2) = max{0, x1 - 5, x2 - 44} true_A = 53 app_A(x1,x2) = max{x1 + 2, x2 + 39} if_A(x1,x2,x3) = max{x1, x2, x3} eq_A(x1,x2) = max{53, x1 - 2, x2 - 2} |0|_A = 0 s_A(x1) = x1 + 1 nil_A = 42 ifmem_A(x1,x2,x3) = max{x1 - 54, x2 - 5, x3 + 53} ifinter#!_A(x1,x2,x3,x4) = max{123, x1 - 54, x2 - 1, x3 + 83, x4 + 82} false!_A = 1 inter#!_A(x1,x2) = max{122, x1 + 83, x2 + 82} cons!_A(x1,x2) = max{76, x1 - 27, x2 - 51} mem!_A(x1,x2) = x1 + 80 true!_A = 75 app!_A(x1,x2) = max{1, x1 - 22, x2 - 44} if!_A(x1,x2,x3) = max{x1, x2, x3} eq!_A(x1,x2) = max{81, x1 - 2, x2 - 2} |0|!_A = 76 s!_A(x1) = max{2, x1 - 3} nil!_A = 77 ifmem!_A(x1,x2,x3) = x2 + 80 partial status: pi(ifinter#) = [] pi(false) = [] pi(inter#) = [] pi(cons) = [] pi(mem) = [1] pi(true) = [] pi(app) = [] pi(if) = [2, 3] pi(eq) = [] pi(|0|) = [] pi(s) = [1] pi(nil) = [] pi(ifmem) = [2] The following rules are removed: p2 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: ifinter#(false(),x,l1,l2) -> inter#(l1,l2) p2: ifinter#(true(),x,l1,l2) -> inter#(l1,l2) p3: inter#(cons(x,l1),l2) -> ifinter#(mem(x,l2),x,l1,l2) p4: inter#(l1,app(l2,l3)) -> inter#(l1,l3) p5: inter#(l1,app(l2,l3)) -> inter#(l1,l2) p6: inter#(app(l1,l2),l3) -> inter#(l2,l3) p7: inter#(app(l1,l2),l3) -> inter#(l1,l3) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) The estimated dependency graph contains the following SCCs: {p1, p2, p3, p4, p5, p6, p7} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: ifinter#(false(),x,l1,l2) -> inter#(l1,l2) p2: inter#(app(l1,l2),l3) -> inter#(l1,l3) p3: inter#(app(l1,l2),l3) -> inter#(l2,l3) p4: inter#(l1,app(l2,l3)) -> inter#(l1,l2) p5: inter#(l1,app(l2,l3)) -> inter#(l1,l3) p6: inter#(cons(x,l1),l2) -> ifinter#(mem(x,l2),x,l1,l2) p7: ifinter#(true(),x,l1,l2) -> inter#(l1,l2) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r10, r11, r12, r13 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: ifinter#_A(x1,x2,x3,x4) = x4 + 19 false_A = 4 inter#_A(x1,x2) = x2 + 19 app_A(x1,x2) = max{5, x1 + 3, x2 + 4} cons_A(x1,x2) = max{6, x1 - 9, x2 - 9} mem_A(x1,x2) = max{8, x1 - 10} true_A = 4 if_A(x1,x2,x3) = max{x2 + 1, x3 + 1} eq_A(x1,x2) = max{7, x1 - 11} |0|_A = 5 s_A(x1) = x1 + 8 nil_A = 0 ifmem_A(x1,x2,x3) = max{8, x1 - 8, x2 - 10} base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: ifinter#_A(x1,x2,x3,x4) = max{0, x1 - 2, x2 - 2, x3 - 2, x4 - 2} false_A = 1 inter#_A(x1,x2) = max{0, x1 - 27, x2 - 2} app_A(x1,x2) = max{14, x1 + 1, x2 + 2} cons_A(x1,x2) = max{x1 + 25, x2 + 25} mem_A(x1,x2) = max{1, x1 - 83} true_A = 1 if_A(x1,x2,x3) = max{x1, x2, x3} eq_A(x1,x2) = max{1, x1 - 2} |0|_A = 1 s_A(x1) = x1 + 1 nil_A = 25 ifmem_A(x1,x2,x3) = max{1, x1 - 81, x2 - 83} ifinter#!_A(x1,x2,x3,x4) = max{x1 + 25, x2 + 28, x3 + 28} false!_A = 21 inter#!_A(x1,x2) = max{27, x1 + 4} app!_A(x1,x2) = max{26, x1 - 32, x2 - 43} cons!_A(x1,x2) = max{25, x1 - 58, x2 - 56} mem!_A(x1,x2) = max{24, x1 - 5, x2 - 26} true!_A = 1 if!_A(x1,x2,x3) = max{x1, x2, x3} eq!_A(x1,x2) = max{23, x1 - 6, x2 - 6} |0|!_A = 22 s!_A(x1) = max{22, x1 - 6} nil!_A = 0 ifmem!_A(x1,x2,x3) = max{24, x1 - 3, x2 - 5, x3 - 26} partial status: pi(ifinter#) = [] pi(false) = [] pi(inter#) = [2] pi(app) = [] pi(cons) = [] pi(mem) = [] pi(true) = [] pi(if) = [2, 3] pi(eq) = [] pi(|0|) = [] pi(s) = [1] pi(nil) = [] pi(ifmem) = [] The following rules are removed: p1, p4, p5, p6, p7 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: inter#(app(l1,l2),l3) -> inter#(l1,l3) p2: inter#(app(l1,l2),l3) -> inter#(l2,l3) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: inter#(app(l1,l2),l3) -> inter#(l1,l3) p2: inter#(app(l1,l2),l3) -> inter#(l2,l3) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) 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: inter#_A(x1,x2) = max{x1 + 2, x2 + 20} app_A(x1,x2) = max{17, x1 + 1, x2 + 1} if_A(x1,x2,x3) = max{x2 + 1, x3 + 1} true_A = 1 false_A = 1 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: inter#_A(x1,x2) = 0 app_A(x1,x2) = max{10, x1 - 26, x2 - 26} if_A(x1,x2,x3) = max{x1, x2, x3} true_A = 1 false_A = 2 inter#!_A(x1,x2) = max{0, x2 - 1} app!_A(x1,x2) = max{6, x1 - 12} if!_A(x1,x2,x3) = max{x1, x2, x3} true!_A = 4 false!_A = 1 partial status: pi(inter#) = [1] pi(app) = [1, 2] pi(if) = [2, 3] pi(true) = [] pi(false) = [] 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: ifmem#(false(),x,l) -> mem#(x,l) p2: mem#(x,cons(y,l)) -> ifmem#(eq(x,y),x,l) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) The set of usable rules consists of r1, r2, r3, r4, r5, r6 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: ifmem#_A(x1,x2,x3) = max{16, x1 - 4, x2 - 4, x3 + 1} false_A = 1 mem#_A(x1,x2) = max{16, x1 - 4, x2 + 1} cons_A(x1,x2) = max{14, x1 + 12, x2 + 12} eq_A(x1,x2) = max{3, x1 - 5, x2 - 5} if_A(x1,x2,x3) = max{x2 + 1, x3 + 1} true_A = 1 |0|_A = 2 s_A(x1) = x1 + 2 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: ifmem#_A(x1,x2,x3) = max{0, x1 - 10, x2 - 9, x3 - 5} false_A = 2 mem#_A(x1,x2) = max{0, x1 - 9, x2 - 6} cons_A(x1,x2) = max{5, x1 - 6, x2 + 1} eq_A(x1,x2) = max{2, x1 - 2, x2 - 2} if_A(x1,x2,x3) = max{x1, x2, x3} true_A = 2 |0|_A = 0 s_A(x1) = x1 + 1 ifmem#!_A(x1,x2,x3) = max{x1 - 15, x2 + 8, x3 - 6} false!_A = 1 mem#!_A(x1,x2) = max{x1 + 8, x2 - 6} cons!_A(x1,x2) = max{6, x1 - 5, x2 - 7} eq!_A(x1,x2) = max{2, x1 - 35, x2 - 35} if!_A(x1,x2,x3) = max{x1, x2, x3} true!_A = 1 |0|!_A = 2 s!_A(x1) = max{1, x1 - 36} partial status: pi(ifmem#) = [3] pi(false) = [] pi(mem#) = [2] pi(cons) = [2] pi(eq) = [] pi(if) = [2, 3] pi(true) = [] pi(|0|) = [] pi(s) = [1] The following rules are removed: p2 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: ifmem#(false(),x,l) -> mem#(x,l) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) The estimated dependency graph contains the following SCCs: (no SCCs) -- 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: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) 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: eq#_A(x1,x2) = 1 s_A(x1) = max{6, x1 - 21} if_A(x1,x2,x3) = max{x2 + 1, x3 + 1} true_A = 2 false_A = 1 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: eq#_A(x1,x2) = max{x1, x2} s_A(x1) = x1 + 8 if_A(x1,x2,x3) = max{x1, x2, x3} true_A = 1 false_A = 2 eq#!_A(x1,x2) = max{3, x1 - 1, x2 - 9} s!_A(x1) = max{2, x1 - 60} if!_A(x1,x2,x3) = max{x1, x2, x3} true!_A = 1 false!_A = 1 partial status: pi(eq#) = [] pi(s) = [] pi(if) = [2, 3] pi(true) = [] 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: app#(cons(x,l1),l2) -> app#(l1,l2) p2: app#(app(l1,l2),l3) -> app#(l2,l3) p3: app#(app(l1,l2),l3) -> app#(l1,app(l2,l3)) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) The set of usable rules consists of r1, r2, r7, r8, r9 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: app#_A(x1,x2) = 1 cons_A(x1,x2) = max{18, x1 - 28, x2 - 14} app_A(x1,x2) = max{x1 + 17, x2} if_A(x1,x2,x3) = max{x2 + 1, x3 + 1} true_A = 2 false_A = 1 nil_A = 2 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: app#_A(x1,x2) = max{0, x1 - 7, x2 - 8} cons_A(x1,x2) = max{4, x1 - 2, x2} app_A(x1,x2) = max{6, x1 + 1, x2} if_A(x1,x2,x3) = max{x1, x2, x3} true_A = 1 false_A = 2 nil_A = 9 app#!_A(x1,x2) = max{11, x1 + 8} cons!_A(x1,x2) = max{9, x1 - 33, x2 - 14} app!_A(x1,x2) = max{10, x1 - 7, x2 - 14} if!_A(x1,x2,x3) = max{x1, x2, x3} true!_A = 3 false!_A = 5 nil!_A = 6 partial status: pi(app#) = [] pi(cons) = [] pi(app) = [1, 2] pi(if) = [2, 3] pi(true) = [] pi(false) = [] pi(nil) = [] The following rules are removed: p3 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: app#(cons(x,l1),l2) -> app#(l1,l2) p2: app#(app(l1,l2),l3) -> app#(l2,l3) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: app#(cons(x,l1),l2) -> app#(l1,l2) p2: app#(app(l1,l2),l3) -> app#(l2,l3) and R consists of: r1: if(true(),x,y) -> x r2: if(false(),x,y) -> y r3: eq(|0|(),|0|()) -> true() r4: eq(|0|(),s(x)) -> false() r5: eq(s(x),|0|()) -> false() r6: eq(s(x),s(y)) -> eq(x,y) r7: app(nil(),l) -> l r8: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r9: app(app(l1,l2),l3) -> app(l1,app(l2,l3)) r10: mem(x,nil()) -> false() r11: mem(x,cons(y,l)) -> ifmem(eq(x,y),x,l) r12: ifmem(true(),x,l) -> true() r13: ifmem(false(),x,l) -> mem(x,l) r14: inter(x,nil()) -> nil() r15: inter(nil(),x) -> nil() r16: inter(app(l1,l2),l3) -> app(inter(l1,l3),inter(l2,l3)) r17: inter(l1,app(l2,l3)) -> app(inter(l1,l2),inter(l1,l3)) r18: inter(cons(x,l1),l2) -> ifinter(mem(x,l2),x,l1,l2) r19: inter(l1,cons(x,l2)) -> ifinter(mem(x,l1),x,l2,l1) r20: ifinter(true(),x,l1,l2) -> cons(x,inter(l1,l2)) r21: ifinter(false(),x,l1,l2) -> inter(l1,l2) 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: app#_A(x1,x2) = max{x1 + 8, x2 + 12} cons_A(x1,x2) = max{3, x1 - 13, x2 + 1} app_A(x1,x2) = max{10, x1 - 15, x2 + 2} if_A(x1,x2,x3) = max{x2 + 1, x3 + 1} true_A = 1 false_A = 1 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: app#_A(x1,x2) = 0 cons_A(x1,x2) = max{28, x1 - 34, x2 - 34} app_A(x1,x2) = max{15, x1 - 48, x2 - 34} if_A(x1,x2,x3) = max{x1, x2, x3} true_A = 1 false_A = 2 app#!_A(x1,x2) = max{0, x2 - 1} cons!_A(x1,x2) = max{2, x1 - 108, x2 - 124} app!_A(x1,x2) = max{7, x1 - 94, x2 - 110} if!_A(x1,x2,x3) = max{x1, x2, x3} true!_A = 5 false!_A = 1 partial status: pi(app#) = [1] pi(cons) = [2] pi(app) = [] pi(if) = [2, 3] pi(true) = [] pi(false) = [] The following rules are removed: p1, p2 Then no dependency pair remains.