YES We show the termination of the TRS R: le(|0|(),y) -> true() le(s(x),|0|()) -> false() le(s(x),s(y)) -> le(x,y) minus(|0|(),y) -> |0|() minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) if_minus(true(),s(x),y) -> |0|() if_minus(false(),s(x),y) -> s(minus(x,y)) quot(|0|(),s(y)) -> |0|() quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) log(s(|0|())) -> |0|() log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: le#(s(x),s(y)) -> le#(x,y) p2: minus#(s(x),y) -> if_minus#(le(s(x),y),s(x),y) p3: minus#(s(x),y) -> le#(s(x),y) p4: if_minus#(false(),s(x),y) -> minus#(x,y) p5: quot#(s(x),s(y)) -> quot#(minus(x,y),s(y)) p6: quot#(s(x),s(y)) -> minus#(x,y) p7: log#(s(s(x))) -> log#(s(quot(x,s(s(|0|()))))) p8: log#(s(s(x))) -> quot#(x,s(s(|0|()))) 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(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The estimated dependency graph contains the following SCCs: {p7} {p5} {p2, p4} {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: log#(s(s(x))) -> log#(s(quot(x,s(s(|0|()))))) 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(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: log#_A(x1) = x1 s_A(x1) = x1 + (0,3) quot_A(x1,x2) = x1 |0|_A() = (0,2) le_A(x1,x2) = (2,5) true_A() = (1,1) false_A() = (1,4) if_minus_A(x1,x2,x3) = x2 minus_A(x1,x2) = x1 precedence: log# > le = true = if_minus = minus > s = quot = |0| = false partial status: pi(log#) = [1] pi(s) = [1] pi(quot) = [1] pi(|0|) = [] pi(le) = [] pi(true) = [] pi(false) = [] pi(if_minus) = [] pi(minus) = [1] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: log#_A(x1) = x1 + (3,4) s_A(x1) = ((1,0),(1,1)) x1 + (5,4) quot_A(x1,x2) = x1 + (1,3) |0|_A() = (2,14) le_A(x1,x2) = (4,7) true_A() = (1,0) false_A() = (1,5) if_minus_A(x1,x2,x3) = (6,15) minus_A(x1,x2) = (0,6) precedence: quot = if_minus = minus > |0| = false > s > log# > le = true partial status: pi(log#) = [1] pi(s) = [1] pi(quot) = [] pi(|0|) = [] pi(le) = [] pi(true) = [] pi(false) = [] pi(if_minus) = [] pi(minus) = [] 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: quot#(s(x),s(y)) -> quot#(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(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: quot#_A(x1,x2) = x1 + (1,1) s_A(x1) = ((1,0),(0,0)) x1 + (5,5) minus_A(x1,x2) = ((1,0),(1,0)) x1 + (4,3) le_A(x1,x2) = ((0,0),(1,0)) x1 + (3,2) |0|_A() = (1,1) true_A() = (2,2) false_A() = (2,6) if_minus_A(x1,x2,x3) = x2 + (4,1) precedence: minus > le > |0| > true > quot# = s = false = if_minus partial status: pi(quot#) = [] pi(s) = [] pi(minus) = [] pi(le) = [] pi(|0|) = [] pi(true) = [] pi(false) = [] pi(if_minus) = [2] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: quot#_A(x1,x2) = (0,1) s_A(x1) = (2,2) minus_A(x1,x2) = (4,3) le_A(x1,x2) = (1,4) |0|_A() = (0,0) true_A() = (0,0) false_A() = (0,0) if_minus_A(x1,x2,x3) = (3,0) precedence: if_minus > quot# = s = minus = le = |0| = true = false partial status: pi(quot#) = [] pi(s) = [] pi(minus) = [] pi(le) = [] pi(|0|) = [] pi(true) = [] pi(false) = [] pi(if_minus) = [] 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: if_minus#(false(),s(x),y) -> minus#(x,y) p2: minus#(s(x),y) -> if_minus#(le(s(x),y),s(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(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The set of usable rules consists of r1, r2, r3 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: if_minus#_A(x1,x2,x3) = x2 + ((0,0),(1,0)) x3 + (1,1) false_A() = (4,1) s_A(x1) = ((1,0),(1,0)) x1 + (3,2) minus#_A(x1,x2) = ((1,0),(0,0)) x1 + (2,0) le_A(x1,x2) = x2 + (2,1) |0|_A() = (5,2) true_A() = (2,1) precedence: false > le = true > |0| > if_minus# = s = minus# partial status: pi(if_minus#) = [2] pi(false) = [] pi(s) = [] pi(minus#) = [] pi(le) = [2] pi(|0|) = [] pi(true) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: if_minus#_A(x1,x2,x3) = (0,1) false_A() = (2,1) s_A(x1) = (1,0) minus#_A(x1,x2) = (0,0) le_A(x1,x2) = ((1,0),(1,1)) x2 + (2,1) |0|_A() = (3,2) true_A() = (0,0) precedence: le > if_minus# = s > minus# > false = |0| > true partial status: pi(if_minus#) = [] pi(false) = [] pi(s) = [] pi(minus#) = [] pi(le) = [2] pi(|0|) = [] pi(true) = [] 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: if_minus#(false(),s(x),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(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The estimated dependency graph contains the following SCCs: (no SCCs) -- Reduction pair. Consider the 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(|0|(),y) -> |0|() r5: minus(s(x),y) -> if_minus(le(s(x),y),s(x),y) r6: if_minus(true(),s(x),y) -> |0|() r7: if_minus(false(),s(x),y) -> s(minus(x,y)) r8: quot(|0|(),s(y)) -> |0|() r9: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r10: log(s(|0|())) -> |0|() r11: log(s(s(x))) -> s(log(s(quot(x,s(s(|0|())))))) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: le#_A(x1,x2) = ((1,0),(0,0)) x1 s_A(x1) = ((1,0),(0,0)) x1 + (1,1) precedence: le# > s partial status: pi(le#) = [] pi(s) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: le#_A(x1,x2) = (0,0) s_A(x1) = (1,1) precedence: le# = s partial status: pi(le#) = [] pi(s) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.