YES We show the termination of the TRS R: +(x,+(y,z)) -> +(+(x,y),z) +(*(x,y),+(x,z)) -> *(x,+(y,z)) +(*(x,y),+(*(x,z),u)) -> +(*(x,+(y,z)),u) -- 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) p3: +#(*(x,y),+(x,z)) -> +#(y,z) p4: +#(*(x,y),+(*(x,z),u)) -> +#(*(x,+(y,z)),u) p5: +#(*(x,y),+(*(x,z),u)) -> +#(y,z) and R consists of: r1: +(x,+(y,z)) -> +(+(x,y),z) r2: +(*(x,y),+(x,z)) -> *(x,+(y,z)) r3: +(*(x,y),+(*(x,z),u)) -> +(*(x,+(y,z)),u) The estimated dependency graph contains the following SCCs: {p1, p2, p3, p4, p5} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: +#(x,+(y,z)) -> +#(+(x,y),z) p2: +#(*(x,y),+(*(x,z),u)) -> +#(y,z) p3: +#(*(x,y),+(*(x,z),u)) -> +#(*(x,+(y,z)),u) p4: +#(*(x,y),+(x,z)) -> +#(y,z) p5: +#(x,+(y,z)) -> +#(x,y) and R consists of: r1: +(x,+(y,z)) -> +(+(x,y),z) r2: +(*(x,y),+(x,z)) -> *(x,+(y,z)) r3: +(*(x,y),+(*(x,z),u)) -> +(*(x,+(y,z)),u) The set of usable rules consists of r1, r2, r3 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) = ((1,0),(0,0)) x1 + ((1,0),(1,0)) x2 + (4,2) +_A(x1,x2) = x1 + ((1,0),(0,0)) x2 + (1,0) *_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (2,1) precedence: +# = + = * partial status: pi(+#) = [] pi(+) = [] pi(*) = [2] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: +#_A(x1,x2) = (0,0) +_A(x1,x2) = (2,4) *_A(x1,x2) = ((0,0),(1,0)) x2 + (1,1) precedence: +# = + = * partial status: pi(+#) = [] pi(+) = [] pi(*) = [] 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) p2: +#(*(x,y),+(*(x,z),u)) -> +#(*(x,+(y,z)),u) p3: +#(*(x,y),+(x,z)) -> +#(y,z) p4: +#(x,+(y,z)) -> +#(x,y) and R consists of: r1: +(x,+(y,z)) -> +(+(x,y),z) r2: +(*(x,y),+(x,z)) -> *(x,+(y,z)) r3: +(*(x,y),+(*(x,z),u)) -> +(*(x,+(y,z)),u) The estimated dependency graph contains the following SCCs: {p1, p2, 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)) -> +#(x,y) p3: +#(*(x,y),+(x,z)) -> +#(y,z) p4: +#(*(x,y),+(*(x,z),u)) -> +#(*(x,+(y,z)),u) and R consists of: r1: +(x,+(y,z)) -> +(+(x,y),z) r2: +(*(x,y),+(x,z)) -> *(x,+(y,z)) r3: +(*(x,y),+(*(x,z),u)) -> +(*(x,+(y,z)),u) The set of usable rules consists of r1, r2, r3 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) = x2 + (2,4) +_A(x1,x2) = ((1,0),(0,0)) x1 + x2 + (3,2) *_A(x1,x2) = x1 + ((1,0),(0,0)) x2 + (1,3) precedence: +# = + = * partial status: pi(+#) = [] pi(+) = [] pi(*) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: +#_A(x1,x2) = (1,1) +_A(x1,x2) = (2,2) *_A(x1,x2) = ((1,0),(1,1)) x1 + (3,3) precedence: +# = + = * partial status: pi(+#) = [] pi(+) = [] pi(*) = [1] 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) p2: +#(*(x,y),+(x,z)) -> +#(y,z) p3: +#(*(x,y),+(*(x,z),u)) -> +#(*(x,+(y,z)),u) and R consists of: r1: +(x,+(y,z)) -> +(+(x,y),z) r2: +(*(x,y),+(x,z)) -> *(x,+(y,z)) r3: +(*(x,y),+(*(x,z),u)) -> +(*(x,+(y,z)),u) The estimated dependency graph contains the following SCCs: {p1, p2, p3} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: +#(x,+(y,z)) -> +#(+(x,y),z) p2: +#(*(x,y),+(*(x,z),u)) -> +#(*(x,+(y,z)),u) p3: +#(*(x,y),+(x,z)) -> +#(y,z) and R consists of: r1: +(x,+(y,z)) -> +(+(x,y),z) r2: +(*(x,y),+(x,z)) -> *(x,+(y,z)) r3: +(*(x,y),+(*(x,z),u)) -> +(*(x,+(y,z)),u) The set of usable rules consists of r1, r2, r3 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 + ((1,0),(1,1)) x2 + (4,3) +_A(x1,x2) = ((1,0),(0,0)) x1 + ((1,0),(0,0)) x2 + (3,2) *_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (2,1) precedence: + > +# = * partial status: pi(+#) = [2] pi(+) = [] pi(*) = [1, 2] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: +#_A(x1,x2) = ((1,0),(1,0)) x2 + (4,3) +_A(x1,x2) = (2,2) *_A(x1,x2) = ((1,0),(1,0)) x1 + ((0,0),(1,0)) x2 + (3,1) precedence: +# = + = * partial status: pi(+#) = [] pi(+) = [] pi(*) = [] The next rules are strictly ordered: p1, p2, p3 We remove them from the problem. Then no dependency pair remains.