YES We show the termination of the TRS R: +(*(x,y),*(a(),y)) -> *(+(x,a()),y) *(*(x,y),z) -> *(x,*(y,z)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: +#(*(x,y),*(a(),y)) -> *#(+(x,a()),y) p2: +#(*(x,y),*(a(),y)) -> +#(x,a()) p3: *#(*(x,y),z) -> *#(x,*(y,z)) p4: *#(*(x,y),z) -> *#(y,z) and R consists of: r1: +(*(x,y),*(a(),y)) -> *(+(x,a()),y) r2: *(*(x,y),z) -> *(x,*(y,z)) The estimated dependency graph contains the following SCCs: {p3, p4} -- 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: +(*(x,y),*(a(),y)) -> *(+(x,a()),y) r2: *(*(x,y),z) -> *(x,*(y,z)) The set of usable rules consists of r2 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: max/plus interpretations on natural numbers: *#_A(x1,x2) = x1 + 4 *_A(x1,x2) = max{x1 + 3, x2} precedence: *# = * partial status: pi(*#) = [] pi(*) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: *#_A(x1,x2) = 0 *_A(x1,x2) = 2 precedence: *# = * partial status: pi(*#) = [] pi(*) = [] 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: *#(*(x,y),z) -> *#(y,z) and R consists of: r1: +(*(x,y),*(a(),y)) -> *(+(x,a()),y) r2: *(*(x,y),z) -> *(x,*(y,z)) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: *#(*(x,y),z) -> *#(y,z) and R consists of: r1: +(*(x,y),*(a(),y)) -> *(+(x,a()),y) r2: *(*(x,y),z) -> *(x,*(y,z)) The set of usable rules consists of (no rules) 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 + 1, x2} *_A(x1,x2) = max{x1 - 1, x2} precedence: *# = * partial status: pi(*#) = [1, 2] pi(*) = [2] 2. weighted path order base order: max/plus interpretations on natural numbers: *#_A(x1,x2) = max{x1 - 1, x2 + 1} *_A(x1,x2) = x2 precedence: *# = * partial status: pi(*#) = [] pi(*) = [2] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.