YES We show the termination of the TRS R: exp(x,|0|()) -> s(|0|()) exp(x,s(y)) -> *(x,exp(x,y)) *(|0|(),y) -> |0|() *(s(x),y) -> +(y,*(x,y)) -(|0|(),y) -> |0|() -(x,|0|()) -> x -(s(x),s(y)) -> -(x,y) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: exp#(x,s(y)) -> *#(x,exp(x,y)) p2: exp#(x,s(y)) -> exp#(x,y) p3: *#(s(x),y) -> *#(x,y) p4: -#(s(x),s(y)) -> -#(x,y) and R consists of: r1: exp(x,|0|()) -> s(|0|()) r2: exp(x,s(y)) -> *(x,exp(x,y)) r3: *(|0|(),y) -> |0|() r4: *(s(x),y) -> +(y,*(x,y)) r5: -(|0|(),y) -> |0|() r6: -(x,|0|()) -> x r7: -(s(x),s(y)) -> -(x,y) The estimated dependency graph contains the following SCCs: {p2} {p3} {p4} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: exp#(x,s(y)) -> exp#(x,y) and R consists of: r1: exp(x,|0|()) -> s(|0|()) r2: exp(x,s(y)) -> *(x,exp(x,y)) r3: *(|0|(),y) -> |0|() r4: *(s(x),y) -> +(y,*(x,y)) r5: -(|0|(),y) -> |0|() r6: -(x,|0|()) -> x r7: -(s(x),s(y)) -> -(x,y) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: exp#_A(x1,x2) = ((0,0),(1,0)) x2 + (1,1) s_A(x1) = x1 + (2,2) precedence: s > exp# partial status: pi(exp#) = [] pi(s) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: exp#_A(x1,x2) = (0,0) s_A(x1) = (1,1) precedence: exp# = s partial status: pi(exp#) = [] pi(s) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: *#(s(x),y) -> *#(x,y) and R consists of: r1: exp(x,|0|()) -> s(|0|()) r2: exp(x,s(y)) -> *(x,exp(x,y)) r3: *(|0|(),y) -> |0|() r4: *(s(x),y) -> +(y,*(x,y)) r5: -(|0|(),y) -> |0|() r6: -(x,|0|()) -> x r7: -(s(x),s(y)) -> -(x,y) The set of usable rules consists of (no rules) 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),(1,1)) x1 + (1,2) s_A(x1) = ((1,0),(0,0)) x1 + (2,1) precedence: s > *# partial status: pi(*#) = [1] pi(s) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: *#_A(x1,x2) = (1,1) s_A(x1) = (2,2) precedence: *# > s partial status: pi(*#) = [] pi(s) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: -#(s(x),s(y)) -> -#(x,y) and R consists of: r1: exp(x,|0|()) -> s(|0|()) r2: exp(x,s(y)) -> *(x,exp(x,y)) r3: *(|0|(),y) -> |0|() r4: *(s(x),y) -> +(y,*(x,y)) r5: -(|0|(),y) -> |0|() r6: -(x,|0|()) -> x r7: -(s(x),s(y)) -> -(x,y) The set of usable rules consists of (no rules) 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 s_A(x1) = ((1,0),(0,0)) x1 + (1,1) precedence: -# > s partial status: pi(-#) = [] pi(s) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: -#_A(x1,x2) = (0,0) s_A(x1) = (1,1) precedence: -# = s partial status: pi(-#) = [] pi(s) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.