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)) gcd(|0|(),y) -> y gcd(s(x),|0|()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) -- 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: gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) p6: gcd#(s(x),s(y)) -> le#(y,x) p7: if_gcd#(true(),s(x),s(y)) -> gcd#(minus(x,y),s(y)) p8: if_gcd#(true(),s(x),s(y)) -> minus#(x,y) p9: if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) p10: if_gcd#(false(),s(x),s(y)) -> minus#(y,x) 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: gcd(|0|(),y) -> y r9: gcd(s(x),|0|()) -> s(x) r10: gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) r11: if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) r12: if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) The estimated dependency graph contains the following SCCs: {p5, p7, p9} {p2, p4} {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) p2: gcd#(s(x),s(y)) -> if_gcd#(le(y,x),s(x),s(y)) p3: if_gcd#(true(),s(x),s(y)) -> gcd#(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: gcd(|0|(),y) -> y r9: gcd(s(x),|0|()) -> s(x) r10: gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) r11: if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) r12: if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: if_gcd#_A(x1,x2,x3) = ((1,0),(1,0)) x2 + x3 + (10,3) false_A() = (4,2) s_A(x1) = ((0,1),(0,1)) x1 + (0,5) gcd#_A(x1,x2) = ((0,1),(0,1)) x1 + ((0,1),(0,1)) x2 + (1,0) minus_A(x1,x2) = x1 + ((1,1),(0,0)) x2 + (18,3) le_A(x1,x2) = ((0,1),(0,1)) x1 + (12,1) true_A() = (19,1) if_minus_A(x1,x2,x3) = ((0,1),(0,1)) x2 + (1,3) |0|_A() = (5,8) precedence: le > s = minus = true = if_minus > if_gcd# = false = gcd# = |0| partial status: pi(if_gcd#) = [] pi(false) = [] pi(s) = [] pi(gcd#) = [] pi(minus) = [1] pi(le) = [] pi(true) = [] pi(if_minus) = [] pi(|0|) = [] The next rules are strictly ordered: p3 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) p2: gcd#(s(x),s(y)) -> if_gcd#(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(|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: gcd(|0|(),y) -> y r9: gcd(s(x),|0|()) -> s(x) r10: gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) r11: if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) r12: if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(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: if_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) p2: gcd#(s(x),s(y)) -> if_gcd#(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(|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: gcd(|0|(),y) -> y r9: gcd(s(x),|0|()) -> s(x) r10: gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) r11: if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) r12: if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: if_gcd#_A(x1,x2,x3) = ((1,0),(0,0)) x1 + x2 + x3 + (1,2) false_A() = (1,1) s_A(x1) = ((1,0),(1,1)) x1 + (5,0) gcd#_A(x1,x2) = x1 + x2 + (4,2) minus_A(x1,x2) = ((1,0),(1,1)) x1 + (2,0) le_A(x1,x2) = ((0,0),(0,1)) x1 + (2,1) if_minus_A(x1,x2,x3) = ((1,0),(1,1)) x2 + (2,0) true_A() = (2,1) |0|_A() = (5,0) precedence: gcd# > minus = le = if_minus > s = true > if_gcd# = false = |0| partial status: pi(if_gcd#) = [] pi(false) = [] pi(s) = [1] pi(gcd#) = [] pi(minus) = [1] pi(le) = [] pi(if_minus) = [2] pi(true) = [] pi(|0|) = [] 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_gcd#(false(),s(x),s(y)) -> gcd#(minus(y,x),s(x)) 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: gcd(|0|(),y) -> y r9: gcd(s(x),|0|()) -> s(x) r10: gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) r11: if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) r12: if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(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: 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: gcd(|0|(),y) -> y r9: gcd(s(x),|0|()) -> s(x) r10: gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) r11: if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) r12: if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) The set of usable rules consists of r1, r2, r3 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: if_minus#_A(x1,x2,x3) = ((1,1),(1,1)) x2 + (1,1) false_A() = (0,2) s_A(x1) = ((1,1),(1,1)) x1 + (1,1) minus#_A(x1,x2) = ((1,1),(1,1)) x1 + (2,3) le_A(x1,x2) = ((1,1),(1,1)) x2 + (5,6) |0|_A() = (2,2) true_A() = (1,1) precedence: le > false = |0| > if_minus# = s = minus# = true partial status: pi(if_minus#) = [] pi(false) = [] pi(s) = [] pi(minus#) = [] pi(le) = [] pi(|0|) = [] pi(true) = [] 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: 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: gcd(|0|(),y) -> y r9: gcd(s(x),|0|()) -> s(x) r10: gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) r11: if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) r12: if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(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: 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: gcd(|0|(),y) -> y r9: gcd(s(x),|0|()) -> s(x) r10: gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) r11: if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) r12: if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: le#_A(x1,x2) = ((0,1),(0,0)) x1 + ((0,1),(0,0)) x2 + (2,2) s_A(x1) = ((0,0),(0,1)) 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.