YES We show the termination of the TRS R: *(i(x),x) -> |1|() *(|1|(),y) -> y *(x,|0|()) -> |0|() *(*(x,y),z) -> *(x,*(y,z)) -- SCC decomposition. 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: *(i(x),x) -> |1|() r2: *(|1|(),y) -> y r3: *(x,|0|()) -> |0|() r4: *(*(x,y),z) -> *(x,*(y,z)) 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) -> *#(y,z) and R consists of: r1: *(i(x),x) -> |1|() r2: *(|1|(),y) -> y r3: *(x,|0|()) -> |0|() r4: *(*(x,y),z) -> *(x,*(y,z)) The set of usable rules consists of r1, r2, r3, r4 Take the reduction pair: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: *#_A(x1,x2) = x1 + x2 *_A(x1,x2) = x1 + x2 + (1,2) i_A(x1) = ((0,0),(1,0)) x1 + (1,1) |1|_A() = (2,1) |0|_A() = (1,0) 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: *(i(x),x) -> |1|() r2: *(|1|(),y) -> y r3: *(x,|0|()) -> |0|() r4: *(*(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) -> *#(x,*(y,z)) and R consists of: r1: *(i(x),x) -> |1|() r2: *(|1|(),y) -> y r3: *(x,|0|()) -> |0|() r4: *(*(x,y),z) -> *(x,*(y,z)) The set of usable rules consists of r1, r2, r3, r4 Take the monotone reduction pair: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: *#_A(x1,x2) = ((1,0),(1,1)) x1 + x2 *_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (1,1) i_A(x1) = ((1,0),(1,1)) x1 + (1,1) |1|_A() = (1,4) |0|_A() = (1,1) The next rules are strictly ordered: p1 r1, r2, r3, r4 We remove them from the problem. Then no dependency pair remains.