YES We show the termination of the TRS R: and(false(),false()) -> false() and(true(),false()) -> false() and(false(),true()) -> false() and(true(),true()) -> true() eq(nil(),nil()) -> true() eq(cons(T,L),nil()) -> false() eq(nil(),cons(T,L)) -> false() eq(cons(T,L),cons(Tp,Lp)) -> and(eq(T,Tp),eq(L,Lp)) eq(var(L),var(Lp)) -> eq(L,Lp) eq(var(L),apply(T,S)) -> false() eq(var(L),lambda(X,T)) -> false() eq(apply(T,S),var(L)) -> false() eq(apply(T,S),apply(Tp,Sp)) -> and(eq(T,Tp),eq(S,Sp)) eq(apply(T,S),lambda(X,Tp)) -> false() eq(lambda(X,T),var(L)) -> false() eq(lambda(X,T),apply(Tp,Sp)) -> false() eq(lambda(X,T),lambda(Xp,Tp)) -> and(eq(T,Tp),eq(X,Xp)) if(true(),var(K),var(L)) -> var(K) if(false(),var(K),var(L)) -> var(L) ren(var(L),var(K),var(Lp)) -> if(eq(L,Lp),var(K),var(Lp)) ren(X,Y,apply(T,S)) -> apply(ren(X,Y,T),ren(X,Y,S)) ren(X,Y,lambda(Z,T)) -> lambda(var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),ren(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: eq#(cons(T,L),cons(Tp,Lp)) -> and#(eq(T,Tp),eq(L,Lp)) p2: eq#(cons(T,L),cons(Tp,Lp)) -> eq#(T,Tp) p3: eq#(cons(T,L),cons(Tp,Lp)) -> eq#(L,Lp) p4: eq#(var(L),var(Lp)) -> eq#(L,Lp) p5: eq#(apply(T,S),apply(Tp,Sp)) -> and#(eq(T,Tp),eq(S,Sp)) p6: eq#(apply(T,S),apply(Tp,Sp)) -> eq#(T,Tp) p7: eq#(apply(T,S),apply(Tp,Sp)) -> eq#(S,Sp) p8: eq#(lambda(X,T),lambda(Xp,Tp)) -> and#(eq(T,Tp),eq(X,Xp)) p9: eq#(lambda(X,T),lambda(Xp,Tp)) -> eq#(T,Tp) p10: eq#(lambda(X,T),lambda(Xp,Tp)) -> eq#(X,Xp) p11: ren#(var(L),var(K),var(Lp)) -> if#(eq(L,Lp),var(K),var(Lp)) p12: ren#(var(L),var(K),var(Lp)) -> eq#(L,Lp) p13: ren#(X,Y,apply(T,S)) -> ren#(X,Y,T) p14: ren#(X,Y,apply(T,S)) -> ren#(X,Y,S) p15: ren#(X,Y,lambda(Z,T)) -> ren#(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T)) p16: ren#(X,Y,lambda(Z,T)) -> ren#(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T) and R consists of: r1: and(false(),false()) -> false() r2: and(true(),false()) -> false() r3: and(false(),true()) -> false() r4: and(true(),true()) -> true() r5: eq(nil(),nil()) -> true() r6: eq(cons(T,L),nil()) -> false() r7: eq(nil(),cons(T,L)) -> false() r8: eq(cons(T,L),cons(Tp,Lp)) -> and(eq(T,Tp),eq(L,Lp)) r9: eq(var(L),var(Lp)) -> eq(L,Lp) r10: eq(var(L),apply(T,S)) -> false() r11: eq(var(L),lambda(X,T)) -> false() r12: eq(apply(T,S),var(L)) -> false() r13: eq(apply(T,S),apply(Tp,Sp)) -> and(eq(T,Tp),eq(S,Sp)) r14: eq(apply(T,S),lambda(X,Tp)) -> false() r15: eq(lambda(X,T),var(L)) -> false() r16: eq(lambda(X,T),apply(Tp,Sp)) -> false() r17: eq(lambda(X,T),lambda(Xp,Tp)) -> and(eq(T,Tp),eq(X,Xp)) r18: if(true(),var(K),var(L)) -> var(K) r19: if(false(),var(K),var(L)) -> var(L) r20: ren(var(L),var(K),var(Lp)) -> if(eq(L,Lp),var(K),var(Lp)) r21: ren(X,Y,apply(T,S)) -> apply(ren(X,Y,T),ren(X,Y,S)) r22: ren(X,Y,lambda(Z,T)) -> lambda(var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),ren(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T))) The estimated dependency graph contains the following SCCs: {p13, p14, p15, p16} {p2, p3, p4, p6, p7, p9, p10} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: ren#(X,Y,lambda(Z,T)) -> ren#(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T) p2: ren#(X,Y,lambda(Z,T)) -> ren#(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T)) p3: ren#(X,Y,apply(T,S)) -> ren#(X,Y,S) p4: ren#(X,Y,apply(T,S)) -> ren#(X,Y,T) and R consists of: r1: and(false(),false()) -> false() r2: and(true(),false()) -> false() r3: and(false(),true()) -> false() r4: and(true(),true()) -> true() r5: eq(nil(),nil()) -> true() r6: eq(cons(T,L),nil()) -> false() r7: eq(nil(),cons(T,L)) -> false() r8: eq(cons(T,L),cons(Tp,Lp)) -> and(eq(T,Tp),eq(L,Lp)) r9: eq(var(L),var(Lp)) -> eq(L,Lp) r10: eq(var(L),apply(T,S)) -> false() r11: eq(var(L),lambda(X,T)) -> false() r12: eq(apply(T,S),var(L)) -> false() r13: eq(apply(T,S),apply(Tp,Sp)) -> and(eq(T,Tp),eq(S,Sp)) r14: eq(apply(T,S),lambda(X,Tp)) -> false() r15: eq(lambda(X,T),var(L)) -> false() r16: eq(lambda(X,T),apply(Tp,Sp)) -> false() r17: eq(lambda(X,T),lambda(Xp,Tp)) -> and(eq(T,Tp),eq(X,Xp)) r18: if(true(),var(K),var(L)) -> var(K) r19: if(false(),var(K),var(L)) -> var(L) r20: ren(var(L),var(K),var(Lp)) -> if(eq(L,Lp),var(K),var(Lp)) r21: ren(X,Y,apply(T,S)) -> apply(ren(X,Y,T),ren(X,Y,S)) r22: ren(X,Y,lambda(Z,T)) -> lambda(var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),ren(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T))) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17, r18, r19, r20, r21, r22 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: ren#_A(x1,x2,x3) = x3 + 58 lambda_A(x1,x2) = max{x1 + 109, x2 + 59} var_A(x1) = 0 cons_A(x1,x2) = max{33, x1 - 121, x2 - 47} nil_A = 0 ren_A(x1,x2,x3) = max{35, x3} apply_A(x1,x2) = max{228, x1 + 159, x2 + 193} and_A(x1,x2) = max{277, x2} false_A = 0 true_A = 0 eq_A(x1,x2) = 278 if_A(x1,x2,x3) = max{x1 - 279, x2 + 35, x3 - 4} precedence: nil > ren = if > true > apply > var > ren# = lambda = cons = and = eq > false partial status: pi(ren#) = [3] pi(lambda) = [1, 2] pi(var) = [] pi(cons) = [] pi(nil) = [] pi(ren) = [3] pi(apply) = [1, 2] pi(and) = [] pi(false) = [] pi(true) = [] pi(eq) = [] pi(if) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: ren#_A(x1,x2,x3) = max{25, x3 - 6} lambda_A(x1,x2) = max{x1 + 7, x2} var_A(x1) = 17 cons_A(x1,x2) = 92 nil_A = 176 ren_A(x1,x2,x3) = max{24, x3 - 6} apply_A(x1,x2) = max{24, x1, x2} and_A(x1,x2) = 52 false_A = 4 true_A = 0 eq_A(x1,x2) = 53 if_A(x1,x2,x3) = 24 precedence: cons = ren > ren# = var > lambda = apply = and = false = true = eq > nil = if partial status: pi(ren#) = [] pi(lambda) = [1] pi(var) = [] pi(cons) = [] pi(nil) = [] pi(ren) = [] pi(apply) = [] pi(and) = [] pi(false) = [] pi(true) = [] pi(eq) = [] pi(if) = [] The next rules are strictly ordered: p4 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: ren#(X,Y,lambda(Z,T)) -> ren#(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T) p2: ren#(X,Y,lambda(Z,T)) -> ren#(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T)) p3: ren#(X,Y,apply(T,S)) -> ren#(X,Y,S) and R consists of: r1: and(false(),false()) -> false() r2: and(true(),false()) -> false() r3: and(false(),true()) -> false() r4: and(true(),true()) -> true() r5: eq(nil(),nil()) -> true() r6: eq(cons(T,L),nil()) -> false() r7: eq(nil(),cons(T,L)) -> false() r8: eq(cons(T,L),cons(Tp,Lp)) -> and(eq(T,Tp),eq(L,Lp)) r9: eq(var(L),var(Lp)) -> eq(L,Lp) r10: eq(var(L),apply(T,S)) -> false() r11: eq(var(L),lambda(X,T)) -> false() r12: eq(apply(T,S),var(L)) -> false() r13: eq(apply(T,S),apply(Tp,Sp)) -> and(eq(T,Tp),eq(S,Sp)) r14: eq(apply(T,S),lambda(X,Tp)) -> false() r15: eq(lambda(X,T),var(L)) -> false() r16: eq(lambda(X,T),apply(Tp,Sp)) -> false() r17: eq(lambda(X,T),lambda(Xp,Tp)) -> and(eq(T,Tp),eq(X,Xp)) r18: if(true(),var(K),var(L)) -> var(K) r19: if(false(),var(K),var(L)) -> var(L) r20: ren(var(L),var(K),var(Lp)) -> if(eq(L,Lp),var(K),var(Lp)) r21: ren(X,Y,apply(T,S)) -> apply(ren(X,Y,T),ren(X,Y,S)) r22: ren(X,Y,lambda(Z,T)) -> lambda(var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),ren(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T))) The estimated dependency graph contains the following SCCs: {p1, p2, p3} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: ren#(X,Y,lambda(Z,T)) -> ren#(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T) p2: ren#(X,Y,apply(T,S)) -> ren#(X,Y,S) p3: ren#(X,Y,lambda(Z,T)) -> ren#(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T)) and R consists of: r1: and(false(),false()) -> false() r2: and(true(),false()) -> false() r3: and(false(),true()) -> false() r4: and(true(),true()) -> true() r5: eq(nil(),nil()) -> true() r6: eq(cons(T,L),nil()) -> false() r7: eq(nil(),cons(T,L)) -> false() r8: eq(cons(T,L),cons(Tp,Lp)) -> and(eq(T,Tp),eq(L,Lp)) r9: eq(var(L),var(Lp)) -> eq(L,Lp) r10: eq(var(L),apply(T,S)) -> false() r11: eq(var(L),lambda(X,T)) -> false() r12: eq(apply(T,S),var(L)) -> false() r13: eq(apply(T,S),apply(Tp,Sp)) -> and(eq(T,Tp),eq(S,Sp)) r14: eq(apply(T,S),lambda(X,Tp)) -> false() r15: eq(lambda(X,T),var(L)) -> false() r16: eq(lambda(X,T),apply(Tp,Sp)) -> false() r17: eq(lambda(X,T),lambda(Xp,Tp)) -> and(eq(T,Tp),eq(X,Xp)) r18: if(true(),var(K),var(L)) -> var(K) r19: if(false(),var(K),var(L)) -> var(L) r20: ren(var(L),var(K),var(Lp)) -> if(eq(L,Lp),var(K),var(Lp)) r21: ren(X,Y,apply(T,S)) -> apply(ren(X,Y,T),ren(X,Y,S)) r22: ren(X,Y,lambda(Z,T)) -> lambda(var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),ren(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T))) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17, r18, r19, r20, r21, r22 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: ren#_A(x1,x2,x3) = max{5, x3 - 103} lambda_A(x1,x2) = x2 + 145 var_A(x1) = 0 cons_A(x1,x2) = 2 nil_A = 144 apply_A(x1,x2) = max{x1 + 14, x2 + 109} ren_A(x1,x2,x3) = x3 and_A(x1,x2) = max{145, x1 - 92, x2 - 7} false_A = 52 true_A = 145 eq_A(x1,x2) = 154 if_A(x1,x2,x3) = max{x1 - 154, x2} precedence: ren# = cons = ren > and > lambda > apply = false > nil > eq > true = if > var partial status: pi(ren#) = [] pi(lambda) = [2] pi(var) = [] pi(cons) = [] pi(nil) = [] pi(apply) = [1, 2] pi(ren) = [] pi(and) = [] pi(false) = [] pi(true) = [] pi(eq) = [] pi(if) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: ren#_A(x1,x2,x3) = 88 lambda_A(x1,x2) = 87 var_A(x1) = 86 cons_A(x1,x2) = 215 nil_A = 48 apply_A(x1,x2) = 87 ren_A(x1,x2,x3) = 87 and_A(x1,x2) = 218 false_A = 111 true_A = 51 eq_A(x1,x2) = 159 if_A(x1,x2,x3) = 86 precedence: ren = false > cons = apply > lambda > ren# = nil > and > true = eq = if > var partial status: pi(ren#) = [] pi(lambda) = [] pi(var) = [] pi(cons) = [] pi(nil) = [] pi(apply) = [] pi(ren) = [] pi(and) = [] pi(false) = [] pi(true) = [] pi(eq) = [] pi(if) = [] The next rules are strictly ordered: p2 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: ren#(X,Y,lambda(Z,T)) -> ren#(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T) p2: ren#(X,Y,lambda(Z,T)) -> ren#(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T)) and R consists of: r1: and(false(),false()) -> false() r2: and(true(),false()) -> false() r3: and(false(),true()) -> false() r4: and(true(),true()) -> true() r5: eq(nil(),nil()) -> true() r6: eq(cons(T,L),nil()) -> false() r7: eq(nil(),cons(T,L)) -> false() r8: eq(cons(T,L),cons(Tp,Lp)) -> and(eq(T,Tp),eq(L,Lp)) r9: eq(var(L),var(Lp)) -> eq(L,Lp) r10: eq(var(L),apply(T,S)) -> false() r11: eq(var(L),lambda(X,T)) -> false() r12: eq(apply(T,S),var(L)) -> false() r13: eq(apply(T,S),apply(Tp,Sp)) -> and(eq(T,Tp),eq(S,Sp)) r14: eq(apply(T,S),lambda(X,Tp)) -> false() r15: eq(lambda(X,T),var(L)) -> false() r16: eq(lambda(X,T),apply(Tp,Sp)) -> false() r17: eq(lambda(X,T),lambda(Xp,Tp)) -> and(eq(T,Tp),eq(X,Xp)) r18: if(true(),var(K),var(L)) -> var(K) r19: if(false(),var(K),var(L)) -> var(L) r20: ren(var(L),var(K),var(Lp)) -> if(eq(L,Lp),var(K),var(Lp)) r21: ren(X,Y,apply(T,S)) -> apply(ren(X,Y,T),ren(X,Y,S)) r22: ren(X,Y,lambda(Z,T)) -> lambda(var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),ren(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T))) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: ren#(X,Y,lambda(Z,T)) -> ren#(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T) p2: ren#(X,Y,lambda(Z,T)) -> ren#(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T)) and R consists of: r1: and(false(),false()) -> false() r2: and(true(),false()) -> false() r3: and(false(),true()) -> false() r4: and(true(),true()) -> true() r5: eq(nil(),nil()) -> true() r6: eq(cons(T,L),nil()) -> false() r7: eq(nil(),cons(T,L)) -> false() r8: eq(cons(T,L),cons(Tp,Lp)) -> and(eq(T,Tp),eq(L,Lp)) r9: eq(var(L),var(Lp)) -> eq(L,Lp) r10: eq(var(L),apply(T,S)) -> false() r11: eq(var(L),lambda(X,T)) -> false() r12: eq(apply(T,S),var(L)) -> false() r13: eq(apply(T,S),apply(Tp,Sp)) -> and(eq(T,Tp),eq(S,Sp)) r14: eq(apply(T,S),lambda(X,Tp)) -> false() r15: eq(lambda(X,T),var(L)) -> false() r16: eq(lambda(X,T),apply(Tp,Sp)) -> false() r17: eq(lambda(X,T),lambda(Xp,Tp)) -> and(eq(T,Tp),eq(X,Xp)) r18: if(true(),var(K),var(L)) -> var(K) r19: if(false(),var(K),var(L)) -> var(L) r20: ren(var(L),var(K),var(Lp)) -> if(eq(L,Lp),var(K),var(Lp)) r21: ren(X,Y,apply(T,S)) -> apply(ren(X,Y,T),ren(X,Y,S)) r22: ren(X,Y,lambda(Z,T)) -> lambda(var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),ren(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T))) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17, r18, r19, r20, r21, r22 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: ren#_A(x1,x2,x3) = x3 + 3 lambda_A(x1,x2) = max{119, x1 + 55, x2 + 50} var_A(x1) = 59 cons_A(x1,x2) = x2 + 28 nil_A = 26 ren_A(x1,x2,x3) = x3 and_A(x1,x2) = max{58, x1 - 72, x2 - 1} false_A = 0 true_A = 25 eq_A(x1,x2) = 58 apply_A(x1,x2) = max{x1 + 28, x2 + 45} if_A(x1,x2,x3) = max{58, x1 - 11, x2} precedence: ren# = cons = nil = true > ren > lambda = false = eq > var = and = apply = if partial status: pi(ren#) = [3] pi(lambda) = [1, 2] pi(var) = [] pi(cons) = [2] pi(nil) = [] pi(ren) = [] pi(and) = [] pi(false) = [] pi(true) = [] pi(eq) = [] pi(apply) = [2] pi(if) = [2] 2. weighted path order base order: max/plus interpretations on natural numbers: ren#_A(x1,x2,x3) = x3 + 98 lambda_A(x1,x2) = max{x1 - 26, x2 + 14} var_A(x1) = 28 cons_A(x1,x2) = max{37, x2 + 17} nil_A = 10 ren_A(x1,x2,x3) = 3 and_A(x1,x2) = 21 false_A = 11 true_A = 22 eq_A(x1,x2) = 21 apply_A(x1,x2) = x2 + 12 if_A(x1,x2,x3) = max{18, x2} precedence: ren# = lambda = var = cons = nil = ren = and = false = true = eq = apply = if partial status: pi(ren#) = [] pi(lambda) = [] pi(var) = [] pi(cons) = [2] pi(nil) = [] pi(ren) = [] pi(and) = [] pi(false) = [] pi(true) = [] pi(eq) = [] pi(apply) = [2] pi(if) = [2] The next rules are strictly ordered: p1, p2 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: eq#(cons(T,L),cons(Tp,Lp)) -> eq#(T,Tp) p2: eq#(lambda(X,T),lambda(Xp,Tp)) -> eq#(X,Xp) p3: eq#(lambda(X,T),lambda(Xp,Tp)) -> eq#(T,Tp) p4: eq#(apply(T,S),apply(Tp,Sp)) -> eq#(S,Sp) p5: eq#(apply(T,S),apply(Tp,Sp)) -> eq#(T,Tp) p6: eq#(var(L),var(Lp)) -> eq#(L,Lp) p7: eq#(cons(T,L),cons(Tp,Lp)) -> eq#(L,Lp) and R consists of: r1: and(false(),false()) -> false() r2: and(true(),false()) -> false() r3: and(false(),true()) -> false() r4: and(true(),true()) -> true() r5: eq(nil(),nil()) -> true() r6: eq(cons(T,L),nil()) -> false() r7: eq(nil(),cons(T,L)) -> false() r8: eq(cons(T,L),cons(Tp,Lp)) -> and(eq(T,Tp),eq(L,Lp)) r9: eq(var(L),var(Lp)) -> eq(L,Lp) r10: eq(var(L),apply(T,S)) -> false() r11: eq(var(L),lambda(X,T)) -> false() r12: eq(apply(T,S),var(L)) -> false() r13: eq(apply(T,S),apply(Tp,Sp)) -> and(eq(T,Tp),eq(S,Sp)) r14: eq(apply(T,S),lambda(X,Tp)) -> false() r15: eq(lambda(X,T),var(L)) -> false() r16: eq(lambda(X,T),apply(Tp,Sp)) -> false() r17: eq(lambda(X,T),lambda(Xp,Tp)) -> and(eq(T,Tp),eq(X,Xp)) r18: if(true(),var(K),var(L)) -> var(K) r19: if(false(),var(K),var(L)) -> var(L) r20: ren(var(L),var(K),var(Lp)) -> if(eq(L,Lp),var(K),var(Lp)) r21: ren(X,Y,apply(T,S)) -> apply(ren(X,Y,T),ren(X,Y,S)) r22: ren(X,Y,lambda(Z,T)) -> lambda(var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),ren(X,Y,ren(Z,var(cons(X,cons(Y,cons(lambda(Z,T),nil())))),T))) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: eq#_A(x1,x2) = max{2, x1 + 1, x2 + 1} cons_A(x1,x2) = max{x1, x2} lambda_A(x1,x2) = max{x1, x2} apply_A(x1,x2) = max{x1, x2} var_A(x1) = max{1, x1} precedence: eq# = cons = lambda = apply = var partial status: pi(eq#) = [1, 2] pi(cons) = [1, 2] pi(lambda) = [1, 2] pi(apply) = [1, 2] pi(var) = [1] 2. weighted path order base order: max/plus interpretations on natural numbers: eq#_A(x1,x2) = max{x1 - 1, x2 + 1} cons_A(x1,x2) = max{x1, x2} lambda_A(x1,x2) = max{x1, x2} apply_A(x1,x2) = max{x1, x2} var_A(x1) = x1 precedence: eq# = cons = lambda = apply = var partial status: pi(eq#) = [2] pi(cons) = [1, 2] pi(lambda) = [1, 2] pi(apply) = [1, 2] pi(var) = [1] The next rules are strictly ordered: p1, p2, p3, p4, p5, p6, p7 We remove them from the problem. Then no dependency pair remains.