YES We show the termination of the TRS R: din(der(plus(X,Y))) -> u21(din(der(X)),X,Y) u21(dout(DX),X,Y) -> u22(din(der(Y)),X,Y,DX) u22(dout(DY),X,Y,DX) -> dout(plus(DX,DY)) din(der(times(X,Y))) -> u31(din(der(X)),X,Y) u31(dout(DX),X,Y) -> u32(din(der(Y)),X,Y,DX) u32(dout(DY),X,Y,DX) -> dout(plus(times(X,DY),times(Y,DX))) din(der(der(X))) -> u41(din(der(X)),X) u41(dout(DX),X) -> u42(din(der(DX)),X,DX) u42(dout(DDX),X,DX) -> dout(DDX) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: din#(der(plus(X,Y))) -> u21#(din(der(X)),X,Y) p2: din#(der(plus(X,Y))) -> din#(der(X)) p3: u21#(dout(DX),X,Y) -> u22#(din(der(Y)),X,Y,DX) p4: u21#(dout(DX),X,Y) -> din#(der(Y)) p5: din#(der(times(X,Y))) -> u31#(din(der(X)),X,Y) p6: din#(der(times(X,Y))) -> din#(der(X)) p7: u31#(dout(DX),X,Y) -> u32#(din(der(Y)),X,Y,DX) p8: u31#(dout(DX),X,Y) -> din#(der(Y)) p9: din#(der(der(X))) -> u41#(din(der(X)),X) p10: din#(der(der(X))) -> din#(der(X)) p11: u41#(dout(DX),X) -> u42#(din(der(DX)),X,DX) p12: u41#(dout(DX),X) -> din#(der(DX)) and R consists of: r1: din(der(plus(X,Y))) -> u21(din(der(X)),X,Y) r2: u21(dout(DX),X,Y) -> u22(din(der(Y)),X,Y,DX) r3: u22(dout(DY),X,Y,DX) -> dout(plus(DX,DY)) r4: din(der(times(X,Y))) -> u31(din(der(X)),X,Y) r5: u31(dout(DX),X,Y) -> u32(din(der(Y)),X,Y,DX) r6: u32(dout(DY),X,Y,DX) -> dout(plus(times(X,DY),times(Y,DX))) r7: din(der(der(X))) -> u41(din(der(X)),X) r8: u41(dout(DX),X) -> u42(din(der(DX)),X,DX) r9: u42(dout(DDX),X,DX) -> dout(DDX) The estimated dependency graph contains the following SCCs: {p1, p2, p4, p5, p6, p8, p9, p10, p12} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: din#(der(plus(X,Y))) -> u21#(din(der(X)),X,Y) p2: u21#(dout(DX),X,Y) -> din#(der(Y)) p3: din#(der(der(X))) -> din#(der(X)) p4: din#(der(der(X))) -> u41#(din(der(X)),X) p5: u41#(dout(DX),X) -> din#(der(DX)) p6: din#(der(times(X,Y))) -> din#(der(X)) p7: din#(der(times(X,Y))) -> u31#(din(der(X)),X,Y) p8: u31#(dout(DX),X,Y) -> din#(der(Y)) p9: din#(der(plus(X,Y))) -> din#(der(X)) and R consists of: r1: din(der(plus(X,Y))) -> u21(din(der(X)),X,Y) r2: u21(dout(DX),X,Y) -> u22(din(der(Y)),X,Y,DX) r3: u22(dout(DY),X,Y,DX) -> dout(plus(DX,DY)) r4: din(der(times(X,Y))) -> u31(din(der(X)),X,Y) r5: u31(dout(DX),X,Y) -> u32(din(der(Y)),X,Y,DX) r6: u32(dout(DY),X,Y,DX) -> dout(plus(times(X,DY),times(Y,DX))) r7: din(der(der(X))) -> u41(din(der(X)),X) r8: u41(dout(DX),X) -> u42(din(der(DX)),X,DX) r9: u42(dout(DDX),X,DX) -> dout(DDX) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9 Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order with precedence: precedence: u22 > u21 > u42 > u41 > u32 > dout > plus > times > u31# > u41# > din > der > u31 > u21# > din# argument filter: pi(din#) = 1 pi(der) = [] pi(plus) = [1, 2] pi(u21#) = 1 pi(din) = 1 pi(dout) = [] pi(u41#) = 1 pi(times) = [] pi(u31#) = 1 pi(u22) = 1 pi(u32) = 1 pi(u42) = 1 pi(u21) = 1 pi(u31) = 1 pi(u41) = 1 2. matrix interpretations: carrier: N^3 order: lexicographic order interpretations: din#_A(x1) = ((0,0,0),(0,0,0),(1,0,0)) x1 + (1,2,1) der_A(x1) = (1,1,1) plus_A(x1,x2) = (0,1,1) u21#_A(x1,x2,x3) = ((0,0,0),(1,0,0),(0,1,0)) x1 din_A(x1) = ((1,0,0),(0,0,0),(0,1,0)) x1 + (0,1,1) dout_A(x1) = (3,3,1) u41#_A(x1,x2) = (0,3,3) times_A(x1,x2) = (1,1,1) u31#_A(x1,x2,x3) = (0,0,0) u22_A(x1,x2,x3,x4) = (4,4,4) u32_A(x1,x2,x3,x4) = (4,4,2) u42_A(x1,x2,x3) = (4,4,2) u21_A(x1,x2,x3) = ((1,0,0),(0,0,0),(0,1,0)) x1 u31_A(x1,x2,x3) = (0,0,0) u41_A(x1,x2) = (0,0,0) The next rules are strictly ordered: p1, p2, p4, p5, p7, p8 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: din#(der(der(X))) -> din#(der(X)) p2: din#(der(times(X,Y))) -> din#(der(X)) p3: din#(der(plus(X,Y))) -> din#(der(X)) and R consists of: r1: din(der(plus(X,Y))) -> u21(din(der(X)),X,Y) r2: u21(dout(DX),X,Y) -> u22(din(der(Y)),X,Y,DX) r3: u22(dout(DY),X,Y,DX) -> dout(plus(DX,DY)) r4: din(der(times(X,Y))) -> u31(din(der(X)),X,Y) r5: u31(dout(DX),X,Y) -> u32(din(der(Y)),X,Y,DX) r6: u32(dout(DY),X,Y,DX) -> dout(plus(times(X,DY),times(Y,DX))) r7: din(der(der(X))) -> u41(din(der(X)),X) r8: u41(dout(DX),X) -> u42(din(der(DX)),X,DX) r9: u42(dout(DDX),X,DX) -> dout(DDX) 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: din#(der(der(X))) -> din#(der(X)) p2: din#(der(plus(X,Y))) -> din#(der(X)) p3: din#(der(times(X,Y))) -> din#(der(X)) and R consists of: r1: din(der(plus(X,Y))) -> u21(din(der(X)),X,Y) r2: u21(dout(DX),X,Y) -> u22(din(der(Y)),X,Y,DX) r3: u22(dout(DY),X,Y,DX) -> dout(plus(DX,DY)) r4: din(der(times(X,Y))) -> u31(din(der(X)),X,Y) r5: u31(dout(DX),X,Y) -> u32(din(der(Y)),X,Y,DX) r6: u32(dout(DY),X,Y,DX) -> dout(plus(times(X,DY),times(Y,DX))) r7: din(der(der(X))) -> u41(din(der(X)),X) r8: u41(dout(DX),X) -> u42(din(der(DX)),X,DX) r9: u42(dout(DDX),X,DX) -> dout(DDX) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order with precedence: precedence: der > times > plus > din# argument filter: pi(din#) = 1 pi(der) = [1] pi(plus) = 1 pi(times) = [1, 2] 2. matrix interpretations: carrier: N^3 order: lexicographic order interpretations: din#_A(x1) = ((1,0,0),(1,1,0),(1,1,1)) x1 der_A(x1) = ((1,0,0),(1,1,0),(0,0,1)) x1 + (1,1,1) plus_A(x1,x2) = x1 + (1,1,1) times_A(x1,x2) = ((1,0,0),(0,1,0),(1,1,1)) x1 + x2 + (1,1,1) The next rules are strictly ordered: p1, p2, p3 We remove them from the problem. Then no dependency pair remains.