YES We show the termination of the TRS R: minus(x,|0|()) -> x minus(s(x),s(y)) -> minus(x,y) quot(|0|(),s(y)) -> |0|() quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: minus#(s(x),s(y)) -> minus#(x,y) p2: quot#(s(x),s(y)) -> quot#(minus(x,y),s(y)) p3: quot#(s(x),s(y)) -> minus#(x,y) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) The estimated dependency graph contains the following SCCs: {p2} {p1} -- 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: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) The set of usable rules consists of r1, r2 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 + x2 s_A(x1) = x1 + (1,0) minus_A(x1,x2) = ((1,0),(0,0)) x1 + (1,0) |0|_A() = (0,1) precedence: quot# = s = minus = |0| partial status: pi(quot#) = [] pi(s) = [] pi(minus) = [] pi(|0|) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: quot#_A(x1,x2) = ((1,0),(0,0)) x1 + ((1,0),(1,1)) x2 s_A(x1) = (2,0) minus_A(x1,x2) = (1,2) |0|_A() = (1,1) precedence: |0| > quot# = s = minus partial status: pi(quot#) = [2] pi(s) = [] pi(minus) = [] pi(|0|) = [] 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: minus#(s(x),s(y)) -> minus#(x,y) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) 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: minus#_A(x1,x2) = ((1,0),(0,0)) x1 s_A(x1) = ((1,0),(0,0)) x1 + (1,1) precedence: minus# > s partial status: pi(minus#) = [] pi(s) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: minus#_A(x1,x2) = (0,0) s_A(x1) = (1,1) precedence: minus# = s partial status: pi(minus#) = [] pi(s) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.