YES We show the termination of the TRS R: a(f(),|0|()) -> a(s(),|0|()) a(d(),|0|()) -> |0|() a(d(),a(s(),x)) -> a(s(),a(s(),a(d(),a(p(),a(s(),x))))) a(f(),a(s(),x)) -> a(d(),a(f(),a(p(),a(s(),x)))) a(p(),a(s(),x)) -> x -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a#(f(),|0|()) -> a#(s(),|0|()) p2: a#(d(),a(s(),x)) -> a#(s(),a(s(),a(d(),a(p(),a(s(),x))))) p3: a#(d(),a(s(),x)) -> a#(s(),a(d(),a(p(),a(s(),x)))) p4: a#(d(),a(s(),x)) -> a#(d(),a(p(),a(s(),x))) p5: a#(d(),a(s(),x)) -> a#(p(),a(s(),x)) p6: a#(f(),a(s(),x)) -> a#(d(),a(f(),a(p(),a(s(),x)))) p7: a#(f(),a(s(),x)) -> a#(f(),a(p(),a(s(),x))) p8: a#(f(),a(s(),x)) -> a#(p(),a(s(),x)) and R consists of: r1: a(f(),|0|()) -> a(s(),|0|()) r2: a(d(),|0|()) -> |0|() r3: a(d(),a(s(),x)) -> a(s(),a(s(),a(d(),a(p(),a(s(),x))))) r4: a(f(),a(s(),x)) -> a(d(),a(f(),a(p(),a(s(),x)))) r5: a(p(),a(s(),x)) -> x The estimated dependency graph contains the following SCCs: {p7} {p4} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: a#(f(),a(s(),x)) -> a#(f(),a(p(),a(s(),x))) and R consists of: r1: a(f(),|0|()) -> a(s(),|0|()) r2: a(d(),|0|()) -> |0|() r3: a(d(),a(s(),x)) -> a(s(),a(s(),a(d(),a(p(),a(s(),x))))) r4: a(f(),a(s(),x)) -> a(d(),a(f(),a(p(),a(s(),x)))) r5: a(p(),a(s(),x)) -> x The set of usable rules consists of r5 Take the reduction pair: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: a#_A(x1,x2) = x2 f_A() = (0,0) a_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (0,1) s_A() = (1,1) p_A() = (0,1) 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: a#(d(),a(s(),x)) -> a#(d(),a(p(),a(s(),x))) and R consists of: r1: a(f(),|0|()) -> a(s(),|0|()) r2: a(d(),|0|()) -> |0|() r3: a(d(),a(s(),x)) -> a(s(),a(s(),a(d(),a(p(),a(s(),x))))) r4: a(f(),a(s(),x)) -> a(d(),a(f(),a(p(),a(s(),x)))) r5: a(p(),a(s(),x)) -> x The set of usable rules consists of r5 Take the reduction pair: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: a#_A(x1,x2) = x2 d_A() = (0,0) a_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (0,1) s_A() = (1,1) p_A() = (0,1) The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.