YES We show the termination of the TRS R: p(s(x)) -> x fac(|0|()) -> s(|0|()) fac(s(x)) -> times(s(x),fac(p(s(x)))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: fac#(s(x)) -> fac#(p(s(x))) p2: fac#(s(x)) -> p#(s(x)) and R consists of: r1: p(s(x)) -> x r2: fac(|0|()) -> s(|0|()) r3: fac(s(x)) -> times(s(x),fac(p(s(x)))) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: fac#(s(x)) -> fac#(p(s(x))) and R consists of: r1: p(s(x)) -> x r2: fac(|0|()) -> s(|0|()) r3: fac(s(x)) -> times(s(x),fac(p(s(x)))) The set of usable rules consists of r1 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: fac#_A(x1) = x1 + (1,2) s_A(x1) = x1 + (1,2) p_A(x1) = ((1,0),(0,0)) x1 + (0,1) precedence: fac# = s = p partial status: pi(fac#) = [] pi(s) = [] pi(p) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: fac#_A(x1) = ((0,0),(1,0)) x1 + (3,1) s_A(x1) = x1 + (2,0) p_A(x1) = (1,4) precedence: fac# = s > p partial status: pi(fac#) = [] pi(s) = [] pi(p) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.