YES We show the termination of the TRS R: eq(|0|(),|0|()) -> true() eq(|0|(),s(X)) -> false() eq(s(X),|0|()) -> false() eq(s(X),s(Y)) -> eq(X,Y) rm(N,nil()) -> nil() rm(N,add(M,X)) -> ifrm(eq(N,M),N,add(M,X)) ifrm(true(),N,add(M,X)) -> rm(N,X) ifrm(false(),N,add(M,X)) -> add(M,rm(N,X)) purge(nil()) -> nil() purge(add(N,X)) -> add(N,purge(rm(N,X))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: eq#(s(X),s(Y)) -> eq#(X,Y) p2: rm#(N,add(M,X)) -> ifrm#(eq(N,M),N,add(M,X)) p3: rm#(N,add(M,X)) -> eq#(N,M) p4: ifrm#(true(),N,add(M,X)) -> rm#(N,X) p5: ifrm#(false(),N,add(M,X)) -> rm#(N,X) p6: purge#(add(N,X)) -> purge#(rm(N,X)) p7: purge#(add(N,X)) -> rm#(N,X) and R consists of: r1: eq(|0|(),|0|()) -> true() r2: eq(|0|(),s(X)) -> false() r3: eq(s(X),|0|()) -> false() r4: eq(s(X),s(Y)) -> eq(X,Y) r5: rm(N,nil()) -> nil() r6: rm(N,add(M,X)) -> ifrm(eq(N,M),N,add(M,X)) r7: ifrm(true(),N,add(M,X)) -> rm(N,X) r8: ifrm(false(),N,add(M,X)) -> add(M,rm(N,X)) r9: purge(nil()) -> nil() r10: purge(add(N,X)) -> add(N,purge(rm(N,X))) The estimated dependency graph contains the following SCCs: {p6} {p2, p4, p5} {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: purge#(add(N,X)) -> purge#(rm(N,X)) and R consists of: r1: eq(|0|(),|0|()) -> true() r2: eq(|0|(),s(X)) -> false() r3: eq(s(X),|0|()) -> false() r4: eq(s(X),s(Y)) -> eq(X,Y) r5: rm(N,nil()) -> nil() r6: rm(N,add(M,X)) -> ifrm(eq(N,M),N,add(M,X)) r7: ifrm(true(),N,add(M,X)) -> rm(N,X) r8: ifrm(false(),N,add(M,X)) -> add(M,rm(N,X)) r9: purge(nil()) -> nil() r10: purge(add(N,X)) -> add(N,purge(rm(N,X))) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^1 order: lexicographic order interpretations: purge#_A(x1) = x1 + 1 add_A(x1,x2) = x2 + 3 rm_A(x1,x2) = x2 eq_A(x1,x2) = 4 |0|_A() = 1 true_A() = 2 s_A(x1) = 0 false_A() = 2 ifrm_A(x1,x2,x3) = x3 nil_A() = 1 precedence: true > add = eq = |0| = s = ifrm > purge# = rm > false = nil partial status: pi(purge#) = [1] pi(add) = [] pi(rm) = [2] pi(eq) = [] pi(|0|) = [] pi(true) = [] pi(s) = [] pi(false) = [] pi(ifrm) = [] pi(nil) = [] 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: ifrm#(false(),N,add(M,X)) -> rm#(N,X) p2: rm#(N,add(M,X)) -> ifrm#(eq(N,M),N,add(M,X)) p3: ifrm#(true(),N,add(M,X)) -> rm#(N,X) and R consists of: r1: eq(|0|(),|0|()) -> true() r2: eq(|0|(),s(X)) -> false() r3: eq(s(X),|0|()) -> false() r4: eq(s(X),s(Y)) -> eq(X,Y) r5: rm(N,nil()) -> nil() r6: rm(N,add(M,X)) -> ifrm(eq(N,M),N,add(M,X)) r7: ifrm(true(),N,add(M,X)) -> rm(N,X) r8: ifrm(false(),N,add(M,X)) -> add(M,rm(N,X)) r9: purge(nil()) -> nil() r10: purge(add(N,X)) -> add(N,purge(rm(N,X))) The set of usable rules consists of r1, r2, r3, r4 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^1 order: lexicographic order interpretations: ifrm#_A(x1,x2,x3) = x2 + x3 + 2 false_A() = 1 add_A(x1,x2) = x1 + x2 + 2 rm#_A(x1,x2) = x1 + x2 + 3 eq_A(x1,x2) = x2 + 1 true_A() = 1 |0|_A() = 2 s_A(x1) = x1 + 2 precedence: ifrm# = add = |0| > false = rm# = eq = true = s partial status: pi(ifrm#) = [3] pi(false) = [] pi(add) = [2] pi(rm#) = [] pi(eq) = [] pi(true) = [] pi(|0|) = [] pi(s) = [1] 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: rm#(N,add(M,X)) -> ifrm#(eq(N,M),N,add(M,X)) p2: ifrm#(true(),N,add(M,X)) -> rm#(N,X) and R consists of: r1: eq(|0|(),|0|()) -> true() r2: eq(|0|(),s(X)) -> false() r3: eq(s(X),|0|()) -> false() r4: eq(s(X),s(Y)) -> eq(X,Y) r5: rm(N,nil()) -> nil() r6: rm(N,add(M,X)) -> ifrm(eq(N,M),N,add(M,X)) r7: ifrm(true(),N,add(M,X)) -> rm(N,X) r8: ifrm(false(),N,add(M,X)) -> add(M,rm(N,X)) r9: purge(nil()) -> nil() r10: purge(add(N,X)) -> add(N,purge(rm(N,X))) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: rm#(N,add(M,X)) -> ifrm#(eq(N,M),N,add(M,X)) p2: ifrm#(true(),N,add(M,X)) -> rm#(N,X) and R consists of: r1: eq(|0|(),|0|()) -> true() r2: eq(|0|(),s(X)) -> false() r3: eq(s(X),|0|()) -> false() r4: eq(s(X),s(Y)) -> eq(X,Y) r5: rm(N,nil()) -> nil() r6: rm(N,add(M,X)) -> ifrm(eq(N,M),N,add(M,X)) r7: ifrm(true(),N,add(M,X)) -> rm(N,X) r8: ifrm(false(),N,add(M,X)) -> add(M,rm(N,X)) r9: purge(nil()) -> nil() r10: purge(add(N,X)) -> add(N,purge(rm(N,X))) The set of usable rules consists of r1, r2, r3, r4 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^1 order: lexicographic order interpretations: rm#_A(x1,x2) = x2 + 2 add_A(x1,x2) = x2 + 5 ifrm#_A(x1,x2,x3) = x3 + 1 eq_A(x1,x2) = 4 true_A() = 3 |0|_A() = 4 s_A(x1) = 5 false_A() = 0 precedence: rm# = add > ifrm# = eq = true = |0| = s = false partial status: pi(rm#) = [2] pi(add) = [2] pi(ifrm#) = [3] pi(eq) = [] pi(true) = [] pi(|0|) = [] pi(s) = [] pi(false) = [] 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: ifrm#(true(),N,add(M,X)) -> rm#(N,X) and R consists of: r1: eq(|0|(),|0|()) -> true() r2: eq(|0|(),s(X)) -> false() r3: eq(s(X),|0|()) -> false() r4: eq(s(X),s(Y)) -> eq(X,Y) r5: rm(N,nil()) -> nil() r6: rm(N,add(M,X)) -> ifrm(eq(N,M),N,add(M,X)) r7: ifrm(true(),N,add(M,X)) -> rm(N,X) r8: ifrm(false(),N,add(M,X)) -> add(M,rm(N,X)) r9: purge(nil()) -> nil() r10: purge(add(N,X)) -> add(N,purge(rm(N,X))) 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: eq(|0|(),|0|()) -> true() r2: eq(|0|(),s(X)) -> false() r3: eq(s(X),|0|()) -> false() r4: eq(s(X),s(Y)) -> eq(X,Y) r5: rm(N,nil()) -> nil() r6: rm(N,add(M,X)) -> ifrm(eq(N,M),N,add(M,X)) r7: ifrm(true(),N,add(M,X)) -> rm(N,X) r8: ifrm(false(),N,add(M,X)) -> add(M,rm(N,X)) r9: purge(nil()) -> nil() r10: purge(add(N,X)) -> add(N,purge(rm(N,X))) The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^1 order: lexicographic order interpretations: eq#_A(x1,x2) = x2 s_A(x1) = x1 + 1 precedence: eq# = s partial status: pi(eq#) = [2] pi(s) = [1] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.