YES We show the termination of the TRS R: *(i(x),x) -> |1|() *(|1|(),y) -> y *(x,|0|()) -> |0|() *(*(x,y),z) -> *(x,*(y,z)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: *#(*(x,y),z) -> *#(x,*(y,z)) p2: *#(*(x,y),z) -> *#(y,z) and R consists of: r1: *(i(x),x) -> |1|() r2: *(|1|(),y) -> y r3: *(x,|0|()) -> |0|() r4: *(*(x,y),z) -> *(x,*(y,z)) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: *#(*(x,y),z) -> *#(x,*(y,z)) p2: *#(*(x,y),z) -> *#(y,z) and R consists of: r1: *(i(x),x) -> |1|() r2: *(|1|(),y) -> y r3: *(x,|0|()) -> |0|() r4: *(*(x,y),z) -> *(x,*(y,z)) The set of usable rules consists of r1, r2, r3, r4 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: *#_A(x1,x2) = max{x1 + 5, x2 + 2} *_A(x1,x2) = max{x1 + 3, x2} i_A(x1) = x1 + 3 |1|_A = 2 |0|_A = 2 precedence: * > i > *# = |1| = |0| partial status: pi(*#) = [1, 2] pi(*) = [1, 2] pi(i) = [1] pi(|1|) = [] pi(|0|) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: *#_A(x1,x2) = x1 + 1 *_A(x1,x2) = max{x1 + 3, x2 + 7} i_A(x1) = x1 + 7 |1|_A = 6 |0|_A = 2 precedence: *# = * = i = |1| = |0| partial status: pi(*#) = [] pi(*) = [1, 2] pi(i) = [1] pi(|1|) = [] pi(|0|) = [] The next rules are strictly ordered: p1, p2 We remove them from the problem. Then no dependency pair remains.