YES We show the termination of the relative TRS R/S: R: le(|0|(),y) -> true() le(s(x),|0|()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,|0|()) -> x minus(s(x),s(y)) -> minus(x,y) mod(|0|(),y) -> |0|() mod(s(x),|0|()) -> |0|() mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) if_mod(false(),s(x),s(y)) -> s(x) 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: le#(s(x),s(y)) -> le#(x,y) p2: minus#(s(x),s(y)) -> minus#(x,y) p3: mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) p4: mod#(s(x),s(y)) -> le#(y,x) p5: if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) p6: if_mod#(true(),s(x),s(y)) -> minus#(x,y) and R consists of: r1: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(x,|0|()) -> x r5: minus(s(x),s(y)) -> minus(x,y) r6: mod(|0|(),y) -> |0|() r7: mod(s(x),|0|()) -> |0|() r8: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r9: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r10: if_mod(false(),s(x),s(y)) -> s(x) r11: rand(x) -> x r12: rand(x) -> rand(s(x)) The estimated dependency graph contains the following SCCs: {p3, p5} {p1} {p2} -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) p2: mod#(s(x),s(y)) -> if_mod#(le(y,x),s(x),s(y)) and R consists of: r1: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(x,|0|()) -> x r5: minus(s(x),s(y)) -> minus(x,y) r6: mod(|0|(),y) -> |0|() r7: mod(s(x),|0|()) -> |0|() r8: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r9: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r10: if_mod(false(),s(x),s(y)) -> s(x) r11: rand(x) -> x r12: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: if_mod#_A(x1,x2,x3) = x2 true_A() = (1,1) s_A(x1) = x1 mod#_A(x1,x2) = x1 minus_A(x1,x2) = x1 le_A(x1,x2) = ((0,0),(0,1)) x1 + (4,0) |0|_A() = (2,1) false_A() = (3,0) mod_A(x1,x2) = x1 + ((1,0),(1,1)) x2 + (4,2) if_mod_A(x1,x2,x3) = x2 + ((1,0),(1,1)) x3 + (4,2) rand_A(x1) = ((1,1),(0,1)) x1 + (1,1) precedence: le = mod = if_mod > s > minus > |0| > if_mod# = true = mod# > false > rand partial status: pi(if_mod#) = [2] pi(true) = [] pi(s) = [1] pi(mod#) = [1] pi(minus) = [1] pi(le) = [] pi(|0|) = [] pi(false) = [] pi(mod) = [1, 2] pi(if_mod) = [2, 3] pi(rand) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: if_mod#_A(x1,x2,x3) = x2 + (2,3) true_A() = (2,2) s_A(x1) = ((0,1),(1,1)) x1 + (0,3) mod#_A(x1,x2) = ((0,1),(0,1)) x1 + (0,3) minus_A(x1,x2) = x1 + (1,0) le_A(x1,x2) = (0,3) |0|_A() = (0,0) false_A() = (0,3) mod_A(x1,x2) = ((1,1),(0,0)) x1 + ((1,0),(1,1)) x2 + (2,1) if_mod_A(x1,x2,x3) = ((1,1),(0,0)) x2 + ((1,0),(1,1)) x3 + (1,1) rand_A(x1) = (1,1) precedence: true > s = mod# = minus = le = |0| = mod = if_mod = rand > if_mod# > false partial status: pi(if_mod#) = [2] pi(true) = [] pi(s) = [] pi(mod#) = [] pi(minus) = [1] pi(le) = [] pi(|0|) = [] pi(false) = [] pi(mod) = [] pi(if_mod) = [3] pi(rand) = [] The next rules are strictly ordered: p2 We remove them from the problem. -- SCC decomposition. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: if_mod#(true(),s(x),s(y)) -> mod#(minus(x,y),s(y)) and R consists of: r1: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(x,|0|()) -> x r5: minus(s(x),s(y)) -> minus(x,y) r6: mod(|0|(),y) -> |0|() r7: mod(s(x),|0|()) -> |0|() r8: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r9: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r10: if_mod(false(),s(x),s(y)) -> s(x) r11: rand(x) -> x r12: rand(x) -> rand(s(x)) The estimated dependency graph contains the following SCCs: (no SCCs) -- 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: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(x,|0|()) -> x r5: minus(s(x),s(y)) -> minus(x,y) r6: mod(|0|(),y) -> |0|() r7: mod(s(x),|0|()) -> |0|() r8: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r9: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r10: if_mod(false(),s(x),s(y)) -> s(x) r11: rand(x) -> x r12: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: le#_A(x1,x2) = max{3, x1 + 1, x2 + 1} s_A(x1) = max{2, x1} le_A(x1,x2) = x2 + 3 |0|_A = 5 true_A = 1 false_A = 0 minus_A(x1,x2) = max{x1, x2 + 2} mod_A(x1,x2) = max{10, x1 + 6, x2 + 9} if_mod_A(x1,x2,x3) = max{x1 + 3, x2 + 6, x3 + 9} rand_A(x1) = max{6, x1 + 3} precedence: le = |0| = true = false = mod = if_mod > s > le# = minus = rand partial status: pi(le#) = [1, 2] pi(s) = [1] pi(le) = [2] pi(|0|) = [] pi(true) = [] pi(false) = [] pi(minus) = [1, 2] pi(mod) = [] pi(if_mod) = [] pi(rand) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: le#_A(x1,x2) = max{4, x1 + 1} s_A(x1) = max{3, x1} le_A(x1,x2) = 6 |0|_A = 0 true_A = 3 false_A = 3 minus_A(x1,x2) = max{6, x1, x2} mod_A(x1,x2) = 5 if_mod_A(x1,x2,x3) = 5 rand_A(x1) = 1 precedence: le# = s = le = |0| = true = false = minus = mod = if_mod = rand partial status: pi(le#) = [1] pi(s) = [1] pi(le) = [] pi(|0|) = [] pi(true) = [] pi(false) = [] pi(minus) = [1, 2] pi(mod) = [] pi(if_mod) = [] 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: minus#(s(x),s(y)) -> minus#(x,y) and R consists of: r1: le(|0|(),y) -> true() r2: le(s(x),|0|()) -> false() r3: le(s(x),s(y)) -> le(x,y) r4: minus(x,|0|()) -> x r5: minus(s(x),s(y)) -> minus(x,y) r6: mod(|0|(),y) -> |0|() r7: mod(s(x),|0|()) -> |0|() r8: mod(s(x),s(y)) -> if_mod(le(y,x),s(x),s(y)) r9: if_mod(true(),s(x),s(y)) -> mod(minus(x,y),s(y)) r10: if_mod(false(),s(x),s(y)) -> s(x) r11: rand(x) -> x r12: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: minus#_A(x1,x2) = max{3, x1 + 1, x2} s_A(x1) = max{2, x1} le_A(x1,x2) = x2 + 3 |0|_A = 5 true_A = 1 false_A = 0 minus_A(x1,x2) = max{x1, x2 + 2} mod_A(x1,x2) = max{10, x1 + 6, x2 + 9} if_mod_A(x1,x2,x3) = max{x1 + 3, x2 + 6, x3 + 9} rand_A(x1) = max{6, x1 + 3} precedence: le = |0| = true = false = mod = if_mod > s > minus# = minus = rand partial status: pi(minus#) = [1, 2] pi(s) = [1] pi(le) = [2] pi(|0|) = [] pi(true) = [] pi(false) = [] pi(minus) = [1, 2] pi(mod) = [] pi(if_mod) = [] pi(rand) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: minus#_A(x1,x2) = max{4, x1 + 1} s_A(x1) = max{3, x1} le_A(x1,x2) = 7 |0|_A = 0 true_A = 5 false_A = 5 minus_A(x1,x2) = max{6, x1, x2} mod_A(x1,x2) = 5 if_mod_A(x1,x2,x3) = 5 rand_A(x1) = 1 precedence: minus# = s = le = |0| = true = false = minus = mod = if_mod = rand partial status: pi(minus#) = [1] pi(s) = [1] pi(le) = [] pi(|0|) = [] pi(true) = [] pi(false) = [] pi(minus) = [1, 2] pi(mod) = [] pi(if_mod) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.