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: max/plus interpretations on natural numbers: *#_A(x1,x2) = max{6, x1 - 2, x2 - 3} *_A(x1,x2) = max{x1 + 12, x2 + 12} minus_A(x1) = max{1, x1 - 2} precedence: *# = * = minus partial status: pi(*#) = [] pi(*) = [] pi(minus) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: *#_A(x1,x2) = 14 *_A(x1,x2) = 12 minus_A(x1) = 13 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: max/plus interpretations on natural numbers: *#_A(x1,x2) = max{x1 + 5, x2 - 4} *_A(x1,x2) = max{x1 + 17, x2 + 16} minus_A(x1) = max{1, x1 - 11} precedence: *# = * = minus partial status: pi(*#) = [] pi(*) = [] pi(minus) = [] 2. weighted path order base order: max/plus interpretations on natural numbers: *#_A(x1,x2) = 0 *_A(x1,x2) = 8 minus_A(x1) = 13 precedence: *# = minus > * partial status: pi(*#) = [] pi(*) = [] pi(minus) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.