YES We show the termination of the TRS R: *(x,*(y,z)) -> *(*(x,y),z) *(x,x) -> x -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: *#(x,*(y,z)) -> *#(*(x,y),z) p2: *#(x,*(y,z)) -> *#(x,y) and R consists of: r1: *(x,*(y,z)) -> *(*(x,y),z) r2: *(x,x) -> x 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)) -> *#(x,y) and R consists of: r1: *(x,*(y,z)) -> *(*(x,y),z) r2: *(x,x) -> x The set of usable rules consists of r1, r2 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: *#_A(x1,x2) = ((1,0),(1,1)) x2 + (1,1) *_A(x1,x2) = ((1,0),(1,0)) x1 + ((1,0),(1,1)) x2 + (2,2) precedence: * > *# partial status: pi(*#) = [] pi(*) = [2] The next rules are strictly ordered: p2 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: *#(x,*(y,z)) -> *#(*(x,y),z) and R consists of: r1: *(x,*(y,z)) -> *(*(x,y),z) r2: *(x,x) -> x 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)) -> *#(*(x,y),z) and R consists of: r1: *(x,*(y,z)) -> *(*(x,y),z) r2: *(x,x) -> x The set of usable rules consists of r1, r2 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: *#_A(x1,x2) = x1 + ((1,0),(1,1)) x2 + (1,1) *_A(x1,x2) = x1 + ((1,0),(1,1)) x2 + (1,1) precedence: *# = * partial status: pi(*#) = [2] pi(*) = [2] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.