YES We show the termination of the TRS R: *(x,*(minus(y),y)) -> *(minus(*(y,y)),x) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: *#(x,*(minus(y),y)) -> *#(minus(*(y,y)),x) p2: *#(x,*(minus(y),y)) -> *#(y,y) and R consists of: r1: *(x,*(minus(y),y)) -> *(minus(*(y,y)),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,*(minus(y),y)) -> *#(minus(*(y,y)),x) p2: *#(x,*(minus(y),y)) -> *#(y,y) and R consists of: r1: *(x,*(minus(y),y)) -> *(minus(*(y,y)),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: *#_A(x1,x2) = ((0,0),(1,0)) x1 + ((0,0),(1,0)) x2 + (1,1) *_A(x1,x2) = x1 + x2 + (3,8) minus_A(x1) = ((1,0),(0,0)) x1 + (2,7) precedence: *# = * > minus partial status: pi(*#) = [] pi(*) = [1] pi(minus) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: *#_A(x1,x2) = (0,0) *_A(x1,x2) = (2,0) minus_A(x1) = (1,1) precedence: * > *# = minus partial status: pi(*#) = [] pi(*) = [] pi(minus) = [] 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,*(minus(y),y)) -> *#(minus(*(y,y)),x) and R consists of: r1: *(x,*(minus(y),y)) -> *(minus(*(y,y)),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,*(minus(y),y)) -> *#(minus(*(y,y)),x) and R consists of: r1: *(x,*(minus(y),y)) -> *(minus(*(y,y)),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: *#_A(x1,x2) = x1 + x2 + (1,2) *_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (2,0) minus_A(x1) = ((1,0),(0,0)) x1 + (1,1) precedence: *# = * = minus partial status: pi(*#) = [] pi(*) = [] pi(minus) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: *#_A(x1,x2) = ((1,0),(0,0)) x2 *_A(x1,x2) = x1 + x2 + (2,2) minus_A(x1) = (1,1) precedence: *# = minus > * partial status: pi(*#) = [] pi(*) = [1] pi(minus) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.