YES We show the termination of the relative TRS R/S: R: eq(|0|(),|0|()) -> true() eq(|0|(),s(x)) -> false() eq(s(x),|0|()) -> false() eq(s(x),s(y)) -> eq(x,y) le(|0|(),y) -> true() le(s(x),|0|()) -> false() le(s(x),s(y)) -> le(x,y) app(nil(),y) -> y app(add(n,x),y) -> add(n,app(x,y)) min(add(n,nil())) -> n min(add(n,add(m,x))) -> if_min(le(n,m),add(n,add(m,x))) if_min(true(),add(n,add(m,x))) -> min(add(n,x)) if_min(false(),add(n,add(m,x))) -> min(add(m,x)) rm(n,nil()) -> nil() rm(n,add(m,x)) -> if_rm(eq(n,m),n,add(m,x)) if_rm(true(),n,add(m,x)) -> rm(n,x) if_rm(false(),n,add(m,x)) -> add(m,rm(n,x)) minsort(nil(),nil()) -> nil() minsort(add(n,x),y) -> if_minsort(eq(n,min(add(n,x))),add(n,x),y) if_minsort(true(),add(n,x),y) -> add(n,minsort(app(rm(n,x),y),nil())) if_minsort(false(),add(n,x),y) -> minsort(x,add(n,y)) S: rand(x) -> x rand(x) -> rand(s(x)) -- SCC decomposition. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: eq#(s(x),s(y)) -> eq#(x,y) p2: le#(s(x),s(y)) -> le#(x,y) p3: app#(add(n,x),y) -> app#(x,y) p4: min#(add(n,add(m,x))) -> if_min#(le(n,m),add(n,add(m,x))) p5: min#(add(n,add(m,x))) -> le#(n,m) p6: if_min#(true(),add(n,add(m,x))) -> min#(add(n,x)) p7: if_min#(false(),add(n,add(m,x))) -> min#(add(m,x)) p8: rm#(n,add(m,x)) -> if_rm#(eq(n,m),n,add(m,x)) p9: rm#(n,add(m,x)) -> eq#(n,m) p10: if_rm#(true(),n,add(m,x)) -> rm#(n,x) p11: if_rm#(false(),n,add(m,x)) -> rm#(n,x) p12: minsort#(add(n,x),y) -> if_minsort#(eq(n,min(add(n,x))),add(n,x),y) p13: minsort#(add(n,x),y) -> eq#(n,min(add(n,x))) p14: minsort#(add(n,x),y) -> min#(add(n,x)) p15: if_minsort#(true(),add(n,x),y) -> minsort#(app(rm(n,x),y),nil()) p16: if_minsort#(true(),add(n,x),y) -> app#(rm(n,x),y) p17: if_minsort#(true(),add(n,x),y) -> rm#(n,x) p18: if_minsort#(false(),add(n,x),y) -> minsort#(x,add(n,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: min(add(n,nil())) -> n r11: min(add(n,add(m,x))) -> if_min(le(n,m),add(n,add(m,x))) r12: if_min(true(),add(n,add(m,x))) -> min(add(n,x)) r13: if_min(false(),add(n,add(m,x))) -> min(add(m,x)) r14: rm(n,nil()) -> nil() r15: rm(n,add(m,x)) -> if_rm(eq(n,m),n,add(m,x)) r16: if_rm(true(),n,add(m,x)) -> rm(n,x) r17: if_rm(false(),n,add(m,x)) -> add(m,rm(n,x)) r18: minsort(nil(),nil()) -> nil() r19: minsort(add(n,x),y) -> if_minsort(eq(n,min(add(n,x))),add(n,x),y) r20: if_minsort(true(),add(n,x),y) -> add(n,minsort(app(rm(n,x),y),nil())) r21: if_minsort(false(),add(n,x),y) -> minsort(x,add(n,y)) r22: rand(x) -> x r23: rand(x) -> rand(s(x)) The estimated dependency graph contains the following SCCs: {p12, p15, p18} {p8, p10, p11} {p1} {p4, p6, p7} {p2} {p3} -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: if_minsort#(false(),add(n,x),y) -> minsort#(x,add(n,y)) p2: minsort#(add(n,x),y) -> if_minsort#(eq(n,min(add(n,x))),add(n,x),y) p3: if_minsort#(true(),add(n,x),y) -> minsort#(app(rm(n,x),y),nil()) 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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: min(add(n,nil())) -> n r11: min(add(n,add(m,x))) -> if_min(le(n,m),add(n,add(m,x))) r12: if_min(true(),add(n,add(m,x))) -> min(add(n,x)) r13: if_min(false(),add(n,add(m,x))) -> min(add(m,x)) r14: rm(n,nil()) -> nil() r15: rm(n,add(m,x)) -> if_rm(eq(n,m),n,add(m,x)) r16: if_rm(true(),n,add(m,x)) -> rm(n,x) r17: if_rm(false(),n,add(m,x)) -> add(m,rm(n,x)) r18: minsort(nil(),nil()) -> nil() r19: minsort(add(n,x),y) -> if_minsort(eq(n,min(add(n,x))),add(n,x),y) r20: if_minsort(true(),add(n,x),y) -> add(n,minsort(app(rm(n,x),y),nil())) r21: if_minsort(false(),add(n,x),y) -> minsort(x,add(n,y)) r22: rand(x) -> x r23: rand(x) -> rand(s(x)) 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, r23 Take the reduction pair: lexicographic combination of reduction pairs: 1. matrix interpretations: carrier: N^2 order: lexicographic order interpretations: if_minsort#_A(x1,x2,x3) = ((1,0),(1,1)) x2 + x3 false_A() = (1,4) add_A(x1,x2) = x1 + x2 + (3,1) minsort#_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (0,3) eq_A(x1,x2) = (2,5) min_A(x1) = x1 + (1,5) true_A() = (2,2) app_A(x1,x2) = x1 + ((1,0),(1,1)) x2 + (0,2) rm_A(x1,x2) = x2 + (0,3) nil_A() = (0,0) |0|_A() = (1,1) s_A(x1) = x1 le_A(x1,x2) = ((1,0),(1,1)) x2 + (3,1) if_min_A(x1,x2) = ((1,0),(1,1)) x2 if_rm_A(x1,x2,x3) = x3 + (0,2) minsort_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (1,2) if_minsort_A(x1,x2,x3) = ((1,0),(1,1)) x2 + x3 + (1,0) rand_A(x1) = x1 + (1,1) 2. lexicographic path order with precedence: precedence: s > rand > if_rm > if_min > app > minsort# > eq > add > true > if_minsort# > false > minsort > rm > if_minsort > min > le > |0| > nil argument filter: pi(if_minsort#) = [2] pi(false) = [] pi(add) = [] pi(minsort#) = [] pi(eq) = [] pi(min) = 1 pi(true) = [] pi(app) = [2] pi(rm) = [] pi(nil) = [] pi(|0|) = [] pi(s) = 1 pi(le) = 2 pi(if_min) = 2 pi(if_rm) = [] pi(minsort) = [] pi(if_minsort) = [2, 3] pi(rand) = [1] The next rules are strictly ordered: p1, p2, p3 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: if_rm#(false(),n,add(m,x)) -> rm#(n,x) p2: rm#(n,add(m,x)) -> if_rm#(eq(n,m),n,add(m,x)) p3: if_rm#(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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: min(add(n,nil())) -> n r11: min(add(n,add(m,x))) -> if_min(le(n,m),add(n,add(m,x))) r12: if_min(true(),add(n,add(m,x))) -> min(add(n,x)) r13: if_min(false(),add(n,add(m,x))) -> min(add(m,x)) r14: rm(n,nil()) -> nil() r15: rm(n,add(m,x)) -> if_rm(eq(n,m),n,add(m,x)) r16: if_rm(true(),n,add(m,x)) -> rm(n,x) r17: if_rm(false(),n,add(m,x)) -> add(m,rm(n,x)) r18: minsort(nil(),nil()) -> nil() r19: minsort(add(n,x),y) -> if_minsort(eq(n,min(add(n,x))),add(n,x),y) r20: if_minsort(true(),add(n,x),y) -> add(n,minsort(app(rm(n,x),y),nil())) r21: if_minsort(false(),add(n,x),y) -> minsort(x,add(n,y)) r22: rand(x) -> x r23: rand(x) -> rand(s(x)) 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, r23 Take the reduction pair: lexicographic combination of reduction pairs: 1. matrix interpretations: carrier: N^2 order: lexicographic order interpretations: if_rm#_A(x1,x2,x3) = x2 + x3 + (0,4) false_A() = (1,3) add_A(x1,x2) = x1 + x2 + (2,1) rm#_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (1,0) eq_A(x1,x2) = x1 + x2 + (1,1) true_A() = (1,1) |0|_A() = (1,1) s_A(x1) = ((1,0),(1,1)) x1 + (0,3) le_A(x1,x2) = x2 + (2,3) app_A(x1,x2) = ((1,0),(1,0)) x1 + ((1,0),(1,1)) x2 nil_A() = (0,0) min_A(x1) = x1 + (1,1) if_min_A(x1,x2) = x2 rm_A(x1,x2) = ((0,0),(1,0)) x1 + x2 + (0,3) if_rm_A(x1,x2,x3) = x3 + (0,2) minsort_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (1,1) if_minsort_A(x1,x2,x3) = ((1,0),(1,0)) x2 + x3 + (1,0) rand_A(x1) = x1 + (1,1) 2. lexicographic path order with precedence: precedence: eq > false > if_rm# > rand > if_minsort > minsort > true > rm > min > app > add > if_rm > if_min > |0| > nil > le > s > rm# argument filter: pi(if_rm#) = [] pi(false) = [] pi(add) = [] pi(rm#) = [] pi(eq) = [1] pi(true) = [] pi(|0|) = [] pi(s) = 1 pi(le) = 2 pi(app) = [2] pi(nil) = [] pi(min) = [] pi(if_min) = [] pi(rm) = [] pi(if_rm) = [] pi(minsort) = [] pi(if_minsort) = [] pi(rand) = [] The next rules are strictly ordered: p1, p2, p3 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal 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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: min(add(n,nil())) -> n r11: min(add(n,add(m,x))) -> if_min(le(n,m),add(n,add(m,x))) r12: if_min(true(),add(n,add(m,x))) -> min(add(n,x)) r13: if_min(false(),add(n,add(m,x))) -> min(add(m,x)) r14: rm(n,nil()) -> nil() r15: rm(n,add(m,x)) -> if_rm(eq(n,m),n,add(m,x)) r16: if_rm(true(),n,add(m,x)) -> rm(n,x) r17: if_rm(false(),n,add(m,x)) -> add(m,rm(n,x)) r18: minsort(nil(),nil()) -> nil() r19: minsort(add(n,x),y) -> if_minsort(eq(n,min(add(n,x))),add(n,x),y) r20: if_minsort(true(),add(n,x),y) -> add(n,minsort(app(rm(n,x),y),nil())) r21: if_minsort(false(),add(n,x),y) -> minsort(x,add(n,y)) r22: rand(x) -> x r23: rand(x) -> rand(s(x)) 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, r23 Take the reduction pair: lexicographic combination of reduction pairs: 1. matrix interpretations: carrier: N^2 order: lexicographic order interpretations: eq#_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 s_A(x1) = x1 + (0,1) eq_A(x1,x2) = (2,5) |0|_A() = (1,1) true_A() = (1,3) false_A() = (1,4) le_A(x1,x2) = x1 + ((0,0),(1,0)) x2 + (2,1) app_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (0,1) nil_A() = (0,1) add_A(x1,x2) = x1 + x2 + (2,2) min_A(x1) = x1 + (1,3) if_min_A(x1,x2) = ((1,0),(1,1)) x2 rm_A(x1,x2) = ((0,0),(1,0)) x1 + x2 + (0,2) if_rm_A(x1,x2,x3) = ((0,0),(1,0)) x2 + x3 + (0,3) minsort_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (1,2) if_minsort_A(x1,x2,x3) = ((1,0),(1,0)) x2 + x3 + (1,1) rand_A(x1) = x1 + (1,1) 2. lexicographic path order with precedence: precedence: s > rand > if_minsort > eq > true > minsort > false > app > add > rm > if_rm > if_min > le > min > nil > |0| > eq# argument filter: pi(eq#) = [1] pi(s) = [1] pi(eq) = [] pi(|0|) = [] pi(true) = [] pi(false) = [] pi(le) = [1] pi(app) = [] pi(nil) = [] pi(add) = [] pi(min) = 1 pi(if_min) = [2] pi(rm) = [] pi(if_rm) = [] pi(minsort) = [] pi(if_minsort) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: if_min#(false(),add(n,add(m,x))) -> min#(add(m,x)) p2: min#(add(n,add(m,x))) -> if_min#(le(n,m),add(n,add(m,x))) p3: if_min#(true(),add(n,add(m,x))) -> min#(add(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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: min(add(n,nil())) -> n r11: min(add(n,add(m,x))) -> if_min(le(n,m),add(n,add(m,x))) r12: if_min(true(),add(n,add(m,x))) -> min(add(n,x)) r13: if_min(false(),add(n,add(m,x))) -> min(add(m,x)) r14: rm(n,nil()) -> nil() r15: rm(n,add(m,x)) -> if_rm(eq(n,m),n,add(m,x)) r16: if_rm(true(),n,add(m,x)) -> rm(n,x) r17: if_rm(false(),n,add(m,x)) -> add(m,rm(n,x)) r18: minsort(nil(),nil()) -> nil() r19: minsort(add(n,x),y) -> if_minsort(eq(n,min(add(n,x))),add(n,x),y) r20: if_minsort(true(),add(n,x),y) -> add(n,minsort(app(rm(n,x),y),nil())) r21: if_minsort(false(),add(n,x),y) -> minsort(x,add(n,y)) r22: rand(x) -> x r23: rand(x) -> rand(s(x)) 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, r23 Take the reduction pair: lexicographic combination of reduction pairs: 1. matrix interpretations: carrier: N^2 order: lexicographic order interpretations: if_min#_A(x1,x2) = ((1,0),(1,1)) x2 false_A() = (1,0) add_A(x1,x2) = x1 + x2 + (4,3) min#_A(x1) = ((1,0),(1,0)) x1 + (1,6) le_A(x1,x2) = x1 + (2,2) true_A() = (1,1) eq_A(x1,x2) = (1,2) |0|_A() = (1,0) s_A(x1) = ((1,0),(1,1)) x1 + (0,1) app_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (0,1) nil_A() = (0,7) min_A(x1) = x1 + (1,1) if_min_A(x1,x2) = x2 rm_A(x1,x2) = ((0,0),(1,0)) x1 + ((1,0),(1,1)) x2 + (0,5) if_rm_A(x1,x2,x3) = ((1,0),(1,0)) x3 minsort_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (1,6) if_minsort_A(x1,x2,x3) = x1 + ((1,0),(1,1)) x2 + x3 rand_A(x1) = ((1,0),(1,0)) x1 + (1,1) 2. lexicographic path order with precedence: precedence: rand > minsort > s > eq > true > false > rm > if_rm > le > add > if_minsort > min > if_min > nil > app > |0| > min# > if_min# argument filter: pi(if_min#) = 2 pi(false) = [] pi(add) = [] pi(min#) = [] pi(le) = 1 pi(true) = [] pi(eq) = [] pi(|0|) = [] pi(s) = [] pi(app) = [1] pi(nil) = [] pi(min) = [] pi(if_min) = [] pi(rm) = [] pi(if_rm) = [] pi(minsort) = [] pi(if_minsort) = [1] pi(rand) = [] The next rules are strictly ordered: p1, p2, p3 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: le#(s(x),s(y)) -> le#(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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: min(add(n,nil())) -> n r11: min(add(n,add(m,x))) -> if_min(le(n,m),add(n,add(m,x))) r12: if_min(true(),add(n,add(m,x))) -> min(add(n,x)) r13: if_min(false(),add(n,add(m,x))) -> min(add(m,x)) r14: rm(n,nil()) -> nil() r15: rm(n,add(m,x)) -> if_rm(eq(n,m),n,add(m,x)) r16: if_rm(true(),n,add(m,x)) -> rm(n,x) r17: if_rm(false(),n,add(m,x)) -> add(m,rm(n,x)) r18: minsort(nil(),nil()) -> nil() r19: minsort(add(n,x),y) -> if_minsort(eq(n,min(add(n,x))),add(n,x),y) r20: if_minsort(true(),add(n,x),y) -> add(n,minsort(app(rm(n,x),y),nil())) r21: if_minsort(false(),add(n,x),y) -> minsort(x,add(n,y)) r22: rand(x) -> x r23: rand(x) -> rand(s(x)) 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, r23 Take the reduction pair: lexicographic combination of reduction pairs: 1. matrix interpretations: carrier: N^2 order: lexicographic order interpretations: le#_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 s_A(x1) = x1 + (0,1) eq_A(x1,x2) = x1 + x2 + (1,3) |0|_A() = (1,1) true_A() = (1,1) false_A() = (1,4) le_A(x1,x2) = x1 + ((0,0),(1,0)) x2 + (2,1) app_A(x1,x2) = x1 + ((1,0),(1,1)) x2 + (0,1) nil_A() = (0,0) add_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (2,1) min_A(x1) = x1 + (1,6) if_min_A(x1,x2) = ((1,0),(1,1)) x2 rm_A(x1,x2) = ((0,0),(1,0)) x1 + ((1,0),(1,0)) x2 + (0,3) if_rm_A(x1,x2,x3) = ((1,0),(1,0)) x3 minsort_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (1,0) if_minsort_A(x1,x2,x3) = ((1,0),(1,0)) x2 + x3 + (1,0) rand_A(x1) = x1 + (1,1) 2. lexicographic path order with precedence: precedence: le# > s > rand > |0| > eq > false > true > minsort > if_minsort > rm > if_rm > if_min > le > min > add > nil > app argument filter: pi(le#) = [1] pi(s) = 1 pi(eq) = 1 pi(|0|) = [] pi(true) = [] pi(false) = [] pi(le) = [1] pi(app) = 2 pi(nil) = [] pi(add) = [] pi(min) = [] pi(if_min) = 2 pi(rm) = [] pi(if_rm) = [] pi(minsort) = [2] pi(if_minsort) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: app#(add(n,x),y) -> app#(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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: min(add(n,nil())) -> n r11: min(add(n,add(m,x))) -> if_min(le(n,m),add(n,add(m,x))) r12: if_min(true(),add(n,add(m,x))) -> min(add(n,x)) r13: if_min(false(),add(n,add(m,x))) -> min(add(m,x)) r14: rm(n,nil()) -> nil() r15: rm(n,add(m,x)) -> if_rm(eq(n,m),n,add(m,x)) r16: if_rm(true(),n,add(m,x)) -> rm(n,x) r17: if_rm(false(),n,add(m,x)) -> add(m,rm(n,x)) r18: minsort(nil(),nil()) -> nil() r19: minsort(add(n,x),y) -> if_minsort(eq(n,min(add(n,x))),add(n,x),y) r20: if_minsort(true(),add(n,x),y) -> add(n,minsort(app(rm(n,x),y),nil())) r21: if_minsort(false(),add(n,x),y) -> minsort(x,add(n,y)) r22: rand(x) -> x r23: rand(x) -> rand(s(x)) 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, r23 Take the reduction pair: lexicographic combination of reduction pairs: 1. matrix interpretations: carrier: N^2 order: lexicographic order interpretations: app#_A(x1,x2) = x1 add_A(x1,x2) = x1 + x2 + (3,1) eq_A(x1,x2) = ((1,0),(1,1)) x1 + (2,1) |0|_A() = (1,2) true_A() = (1,2) s_A(x1) = ((1,0),(1,1)) x1 + (0,1) false_A() = (1,3) le_A(x1,x2) = (2,1) app_A(x1,x2) = x1 + ((1,0),(1,1)) x2 + (0,1) nil_A() = (0,1) min_A(x1) = ((1,0),(1,1)) x1 + (1,2) if_min_A(x1,x2) = ((1,0),(1,1)) x2 rm_A(x1,x2) = ((0,0),(1,0)) x1 + ((1,0),(1,0)) x2 + (0,4) if_rm_A(x1,x2,x3) = ((1,0),(1,0)) x3 minsort_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (0,1) if_minsort_A(x1,x2,x3) = ((1,0),(1,0)) x2 + x3 rand_A(x1) = ((1,0),(1,0)) x1 + (1,1) 2. lexicographic path order with precedence: precedence: s > rand > if_rm > if_min > eq > false > |0| > true > add > minsort > app > if_minsort > nil > rm > le > min > app# argument filter: pi(app#) = [] pi(add) = [] pi(eq) = [1] pi(|0|) = [] pi(true) = [] pi(s) = [] pi(false) = [] pi(le) = [] pi(app) = [1] pi(nil) = [] pi(min) = 1 pi(if_min) = 2 pi(rm) = [] pi(if_rm) = [] pi(minsort) = [2] pi(if_minsort) = 3 pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.