YES We show the termination of the TRS R: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: plus#(s(X),plus(Y,Z)) -> plus#(X,plus(s(s(Y)),Z)) p2: plus#(s(X),plus(Y,Z)) -> plus#(s(s(Y)),Z) p3: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X1,plus(X3,plus(X2,X4))) p4: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X3,plus(X2,X4)) p5: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X2,X4) and R consists of: r1: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) r2: plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) 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: plus#(s(X),plus(Y,Z)) -> plus#(X,plus(s(s(Y)),Z)) p2: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X2,X4) p3: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X3,plus(X2,X4)) p4: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X1,plus(X3,plus(X2,X4))) p5: plus#(s(X),plus(Y,Z)) -> plus#(s(s(Y)),Z) and R consists of: r1: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) r2: plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) The set of usable rules consists of r1, r2 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: plus#_A(x1,x2) = ((0,1),(0,0)) x2 + (3,7) s_A(x1) = (1,1) plus_A(x1,x2) = ((0,0),(1,1)) x2 + (2,2) precedence: plus# = s = plus partial status: pi(plus#) = [] pi(s) = [] pi(plus) = [] The next rules are strictly ordered: p3 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: plus#(s(X),plus(Y,Z)) -> plus#(X,plus(s(s(Y)),Z)) p2: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X2,X4) p3: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X1,plus(X3,plus(X2,X4))) p4: plus#(s(X),plus(Y,Z)) -> plus#(s(s(Y)),Z) and R consists of: r1: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) r2: plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) 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: plus#(s(X),plus(Y,Z)) -> plus#(X,plus(s(s(Y)),Z)) p2: plus#(s(X),plus(Y,Z)) -> plus#(s(s(Y)),Z) p3: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X1,plus(X3,plus(X2,X4))) p4: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X2,X4) and R consists of: r1: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) r2: plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) The set of usable rules consists of r1, r2 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: plus#_A(x1,x2) = ((0,1),(0,0)) x2 + (9,5) s_A(x1) = ((0,0),(0,1)) x1 + (8,3) plus_A(x1,x2) = ((0,1),(0,0)) x1 + ((0,0),(0,1)) x2 + (1,2) precedence: plus > plus# = s partial status: pi(plus#) = [] pi(s) = [] pi(plus) = [] 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: plus#(s(X),plus(Y,Z)) -> plus#(X,plus(s(s(Y)),Z)) p2: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X1,plus(X3,plus(X2,X4))) p3: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X2,X4) and R consists of: r1: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) r2: plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) 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: plus#(s(X),plus(Y,Z)) -> plus#(X,plus(s(s(Y)),Z)) p2: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X2,X4) p3: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X1,plus(X3,plus(X2,X4))) and R consists of: r1: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) r2: plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) The set of usable rules consists of r1, r2 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: plus#_A(x1,x2) = x2 + (1,2) s_A(x1) = (2,0) plus_A(x1,x2) = ((0,1),(1,0)) x2 + (3,1) precedence: s > plus# = plus partial status: pi(plus#) = [2] pi(s) = [] pi(plus) = [] 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: plus#(s(X),plus(Y,Z)) -> plus#(X,plus(s(s(Y)),Z)) p2: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X1,plus(X3,plus(X2,X4))) and R consists of: r1: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) r2: plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: plus#(s(X),plus(Y,Z)) -> plus#(X,plus(s(s(Y)),Z)) p2: plus#(s(X1),plus(X2,plus(X3,X4))) -> plus#(X1,plus(X3,plus(X2,X4))) and R consists of: r1: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) r2: plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) The set of usable rules consists of r1, r2 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: plus#_A(x1,x2) = ((0,1),(0,1)) x1 + (3,7) s_A(x1) = ((0,0),(0,1)) x1 + (1,2) plus_A(x1,x2) = ((0,1),(0,0)) x1 + ((0,0),(0,1)) x2 + (2,3) precedence: plus# > s = plus partial status: pi(plus#) = [] pi(s) = [] pi(plus) = [] 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: plus#(s(X),plus(Y,Z)) -> plus#(X,plus(s(s(Y)),Z)) and R consists of: r1: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) r2: plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: plus#(s(X),plus(Y,Z)) -> plus#(X,plus(s(s(Y)),Z)) and R consists of: r1: plus(s(X),plus(Y,Z)) -> plus(X,plus(s(s(Y)),Z)) r2: plus(s(X1),plus(X2,plus(X3,X4))) -> plus(X1,plus(X3,plus(X2,X4))) The set of usable rules consists of r1, r2 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: plus#_A(x1,x2) = ((1,0),(1,0)) x1 + x2 + (0,1) s_A(x1) = ((1,0),(0,0)) x1 + (2,1) plus_A(x1,x2) = ((0,0),(1,1)) x2 + (3,2) precedence: plus# = s = plus partial status: pi(plus#) = [2] pi(s) = [] pi(plus) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.